855645975815 has 4 divisors (see below), whose sum is σ = 1026775170984. Its totient is φ = 684516780648.

The previous prime is 855645975803. The next prime is 855645975857. The reversal of 855645975815 is 518579546558.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 518579546558 = 2 ⋅259289773279.

It is a cyclic number.

It is not a de Polignac number, because 855645975815 - 2³⁸ = 580768068871 is a prime.

It is a super-3 number, since 3×855645975815³ (a number of 37 digits) contains 333 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 85564597577 + ... + 85564597586.

It is an arithmetic number, because the mean of its divisors is an integer number (256693792746).

Almost surely, 2^855645975815 is an apocalyptic number.

855645975815 is a deficient number, since it is larger than the sum of its proper divisors (171129195169).

855645975815 is a wasteful number, since it uses less digits than its factorization.

855645975815 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 171129195168.

The product of its digits is 302400000, while the sum is 68.

The spelling of 855645975815 in words is "eight hundred fifty-five billion, six hundred forty-five million, nine hundred seventy-five thousand, eight hundred fifteen".