21145512480625 has 45 divisors (see below), whose sum is σ = 28614378149973. Its totient is φ = 15614044056000.

The previous prime is 21145512480623. The next prime is 21145512480629. The reversal of 21145512480625 is 52608421554112.

The square root of 21145512480625 is 4598425.

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

It can be written as a sum of positive squares in 22 ways, for example, as 20722679615089 + 422832865536 = 4552217^2 + 650256^2 .

It is not a de Polignac number, because 21145512480625 - 2¹ = 21145512480623 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21145512480623) 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, 1494481051 + ... + 1494495199.

Almost surely, 2^{21145512480625} is an apocalyptic number.

21145512480625 is a gapful number since it is divisible by the number (25) formed by its first and last digit.

21145512480625 is the 4598425-th square number.

21145512480625 is the 2299213-rd centered octagonal number.

It is an amenable number.

21145512480625 is a deficient number, since it is larger than the sum of its proper divisors (7468865669348).

21145512480625 is an frugal number, since it uses more digits than its factorization.

21145512480625 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 28344 (or 14167 counting only the distinct ones).

The product of its (nonzero) digits is 768000, while the sum is 46.

The spelling of 21145512480625 in words is "twenty-one trillion, one hundred forty-five billion, five hundred twelve million, four hundred eighty thousand, six hundred twenty-five".