20156243265 has 24 divisors (see below), whose sum is σ = 35283412008. Its totient is φ = 10643558400.

The previous prime is 20156243251. The next prime is 20156243287. The reversal of 20156243265 is 56234265102.

20156243265 is a `hidden beast` number, since 2 + 0 + 1 + 5 + 624 + 3 + 26 + 5 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 3770451216 + 16385792049 = 61404^2 + 128007^2 .

It is not a de Polignac number, because 20156243265 - 2²¹ = 20154146113 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2212864 + ... + 2221953.

It is an arithmetic number, because the mean of its divisors is an integer number (1470142167).

Almost surely, 2^20156243265 is an apocalyptic number.

It is an amenable number.

20156243265 is a deficient number, since it is larger than the sum of its proper divisors (15127168743).

20156243265 is a wasteful number, since it uses less digits than its factorization.

20156243265 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4434929 (or 4434926 counting only the distinct ones).

The product of its (nonzero) digits is 86400, while the sum is 36.

The spelling of 20156243265 in words is "twenty billion, one hundred fifty-six million, two hundred forty-three thousand, two hundred sixty-five".