856436015652581 has 16 divisors (see below), whose sum is σ = 1054080646881024. Its totient is φ = 677616136389504.

The previous prime is 856436015652521. The next prime is 856436015652601. The reversal of 856436015652581 is 185256510634658.

It is a happy number.

It is not a de Polignac number, because 856436015652581 - 2³⁸ = 856161137745637 is a prime.

It is a super-2 number, since 2×856436015652581² (a number of 31 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (856436015652521) 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, 7336961 + ... + 42032166.

It is an arithmetic number, because the mean of its divisors is an integer number (65880040430064).

Almost surely, 2^{856436015652581} is an apocalyptic number.

It is an amenable number.

856436015652581 is a deficient number, since it is larger than the sum of its proper divisors (197644631228443).

856436015652581 is a wasteful number, since it uses less digits than its factorization.

856436015652581 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 49559780.

The product of its (nonzero) digits is 207360000, while the sum is 65.

The spelling of 856436015652581 in words is "eight hundred fifty-six trillion, four hundred thirty-six billion, fifteen million, six hundred fifty-two thousand, five hundred eighty-one".