261572162345 has 32 divisors (see below), whose sum is σ = 357996270240. Its totient is φ = 181757767680.

The previous prime is 261572162339. The next prime is 261572162389. The reversal of 261572162345 is 543261275162.

It can be written as a sum of positive squares in 16 ways, for example, as 50325294889 + 211246867456 = 224333^2 + 459616^2 .

It is not a de Polignac number, because 261572162345 - 2⁶ = 261572162281 is a prime.

It is a super-2 number, since 2×261572162345² (a number of 24 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 261572162296 and 261572162305.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 5400335 + ... + 5448555.

It is an arithmetic number, because the mean of its divisors is an integer number (11187383445).

Almost surely, 2^261572162345 is an apocalyptic number.

It is an amenable number.

261572162345 is a deficient number, since it is larger than the sum of its proper divisors (96424107895).

261572162345 is a wasteful number, since it uses less digits than its factorization.

261572162345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 53165.

The product of its digits is 604800, while the sum is 44.

The spelling of 261572162345 in words is "two hundred sixty-one billion, five hundred seventy-two million, one hundred sixty-two thousand, three hundred forty-five".