261553772162515 has 16 divisors (see below), whose sum is σ = 365470284339648. Its totient is φ = 175967173938816.

The previous prime is 261553772162497. The next prime is 261553772162591. The reversal of 261553772162515 is 515261277355162.

It is a cyclic number.

It is not a de Polignac number, because 261553772162515 - 2³⁵ = 261519412424147 is a prime.

It is a super-2 number, since 2×261553772162515² (a number of 30 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 261553772162515.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 70499667192 + ... + 70499670901.

It is an arithmetic number, because the mean of its divisors is an integer number (22841892771228).

Almost surely, 2^{261553772162515} is an apocalyptic number.

261553772162515 is a deficient number, since it is larger than the sum of its proper divisors (103916512177133).

261553772162515 is a wasteful number, since it uses less digits than its factorization.

261553772162515 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 140999338158.

The product of its digits is 26460000, while the sum is 58.

The spelling of 261553772162515 in words is "two hundred sixty-one trillion, five hundred fifty-three billion, seven hundred seventy-two million, one hundred sixty-two thousand, five hundred fifteen".