12171605625 has 45 divisors (see below), whose sum is σ = 21984422889. Its totient is φ = 6487110000.

The previous prime is 12171605591. The next prime is 12171605627. The reversal of 12171605625 is 52650617121.

The square root of 12171605625 is 110325.

It is a perfect power (a square), and thus also a powerful number.

12171605625 is a `hidden beast` number, since 1 + 2 + 17 + 16 + 0 + 5 + 625 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 954253881 + 11217351744 = 30891^2 + 105912^2 .

It is a tau number, because it is divible by the number of its divisors (45).

It is not a de Polignac number, because 12171605625 - 2¹³ = 12171597433 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 12171605625.

It is not an unprimeable number, because it can be changed into a prime (12171605627) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 44 ways as a sum of consecutive naturals, for example, 8273640 + ... + 8275110.

Almost surely, 2^12171605625 is an apocalyptic number.

12171605625 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

12171605625 is the 110325-th square number.

12171605625 is the 55163-rd centered octagonal number.

It is an amenable number.

12171605625 is a deficient number, since it is larger than the sum of its proper divisors (9812817264).

12171605625 is an frugal number, since it uses more digits than its factorization.

12171605625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2968 (or 1479 counting only the distinct ones).

The product of its (nonzero) digits is 25200, while the sum is 36.

Multiplying 12171605625 by its sum of digits (36), we get a square (438177802500 = 661950²).

It can be divided in two parts, 12171 and 605625, that added together give a square (617796 = 786²).

The spelling of 12171605625 in words is "twelve billion, one hundred seventy-one million, six hundred five thousand, six hundred twenty-five".