861255516539 has 32 divisors (see below), whose sum is σ = 957690107136. Its totient is φ = 768023118720.

The previous prime is 861255516533. The next prime is 861255516559. The reversal of 861255516539 is 935615552168.

It is not a de Polignac number, because 861255516539 - 2²⁴ = 861238739323 is a prime.

It is a super-2 number, since 2×861255516539² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (861255516533) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 54135224 + ... + 54151130.

It is an arithmetic number, because the mean of its divisors is an integer number (29927815848).

Almost surely, 2^861255516539 is an apocalyptic number.

861255516539 is a deficient number, since it is larger than the sum of its proper divisors (96434590597).

861255516539 is a wasteful number, since it uses less digits than its factorization.

861255516539 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16475.

The product of its digits is 9720000, while the sum is 56.

The spelling of 861255516539 in words is "eight hundred sixty-one billion, two hundred fifty-five million, five hundred sixteen thousand, five hundred thirty-nine".