261216556139 has 16 divisors (see below), whose sum is σ = 329030048256. Its totient is φ = 201446956800.

The previous prime is 261216556099. The next prime is 261216556157. The reversal of 261216556139 is 931655612162.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-261216556139 is a prime.

It is a super-2 number, since 2×261216556139² (a number of 24 digits) contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 261216556093 and 261216556102.

It is not an unprimeable number, because it can be changed into a prime (261216556169) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 17479247 + ... + 17494184.

It is an arithmetic number, because the mean of its divisors is an integer number (20564378016).

Almost surely, 2^261216556139 is an apocalyptic number.

261216556139 is a deficient number, since it is larger than the sum of its proper divisors (67813492117).

261216556139 is a wasteful number, since it uses less digits than its factorization.

261216556139 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 34973546.

The product of its digits is 583200, while the sum is 47.

The spelling of 261216556139 in words is "two hundred sixty-one billion, two hundred sixteen million, five hundred fifty-six thousand, one hundred thirty-nine".