155891256857 has 16 divisors (see below), whose sum is σ = 185950380672. Its totient is φ = 127902353280.

The previous prime is 155891256809. The next prime is 155891256883. The reversal of 155891256857 is 758652198551.

It is a cyclic number.

It is not a de Polignac number, because 155891256857 - 2¹⁰ = 155891255833 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 155891256857.

It is not an unprimeable number, because it can be changed into a prime (155891256757) 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, 5109083 + ... + 5139504.

It is an arithmetic number, because the mean of its divisors is an integer number (11621898792).

Almost surely, 2^155891256857 is an apocalyptic number.

It is an amenable number.

155891256857 is a deficient number, since it is larger than the sum of its proper divisors (30059123815).

155891256857 is a wasteful number, since it uses less digits than its factorization.

155891256857 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10248688.

The product of its digits is 30240000, while the sum is 62.

The spelling of 155891256857 in words is "one hundred fifty-five billion, eight hundred ninety-one million, two hundred fifty-six thousand, eight hundred fifty-seven".