71550365121 has 21 divisors (see below), whose sum is σ = 107287302801. Its totient is φ = 47695428612.

The previous prime is 71550365111. The next prime is 71550365171. The reversal of 71550365121 is 12156305517.

It is a happy number.

The square root of 71550365121 is 267489.

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

71550365121 is a `hidden beast` number, since 7 + 1 + 550 + 36 + 51 + 21 = 666.

It is not a de Polignac number, because 71550365121 - 2⁷ = 71550364993 is a prime.

It is not an unprimeable number, because it can be changed into a prime (71550365111) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 20 ways as a sum of consecutive naturals, for example, 7217250 + ... + 7227156.

It is an arithmetic number, because the mean of its divisors is an integer number (5108919181).

Almost surely, 2^71550365121 is an apocalyptic number.

71550365121 is the 267489-th square number.

71550365121 is the 133745-th centered octagonal number.

It is an amenable number.

71550365121 is a deficient number, since it is larger than the sum of its proper divisors (35736937680).

71550365121 is an frugal number, since it uses more digits than its factorization.

71550365121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 19832 (or 9910 counting only the distinct ones).

The product of its (nonzero) digits is 31500, while the sum is 36.

Multiplying 71550365121 by its sum of digits (36), we get a square (2575813144356 = 1604934²).

The spelling of 71550365121 in words is "seventy-one billion, five hundred fifty million, three hundred sixty-five thousand, one hundred twenty-one".