655821503257 has 16 divisors (see below), whose sum is σ = 666505819008. Its totient is φ = 645185312640.

The previous prime is 655821503219. The next prime is 655821503303. The reversal of 655821503257 is 752305128556.

It is a cyclic number.

It is not a de Polignac number, because 655821503257 - 2³⁹ = 106065689369 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 655821503257.

It is not an unprimeable number, because it can be changed into a prime (655821503957) 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, 49004707 + ... + 49018087.

It is an arithmetic number, because the mean of its divisors is an integer number (41656613688).

Almost surely, 2^655821503257 is an apocalyptic number.

It is an amenable number.

655821503257 is a deficient number, since it is larger than the sum of its proper divisors (10684315751).

655821503257 is a wasteful number, since it uses less digits than its factorization.

655821503257 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15120.

The product of its (nonzero) digits is 2520000, while the sum is 49.

The spelling of 655821503257 in words is "six hundred fifty-five billion, eight hundred twenty-one million, five hundred three thousand, two hundred fifty-seven".