856338240591 has 64 divisors (see below), whose sum is σ = 1358553047040. Its totient is φ = 531786689280.

The previous prime is 856338240587. The next prime is 856338240617. The reversal of 856338240591 is 195042833658.

856338240591 is a `hidden beast` number, since 8 + 5 + 6 + 3 + 3 + 8 + 2 + 40 + 591 = 666.

It is not a de Polignac number, because 856338240591 - 2² = 856338240587 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (856338240521) by changing a digit.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 14151586 + ... + 14211968.

It is an arithmetic number, because the mean of its divisors is an integer number (21227391360).

Almost surely, 2^856338240591 is an apocalyptic number.

856338240591 is a deficient number, since it is larger than the sum of its proper divisors (502214806449).

856338240591 is a wasteful number, since it uses less digits than its factorization.

856338240591 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61013 (or 61007 counting only the distinct ones).

The product of its (nonzero) digits is 6220800, while the sum is 54.

The spelling of 856338240591 in words is "eight hundred fifty-six billion, three hundred thirty-eight million, two hundred forty thousand, five hundred ninety-one".