870120891657 has 64 divisors (see below), whose sum is σ = 1380911616000. Its totient is φ = 539844398784.

The previous prime is 870120891649. The next prime is 870120891683. The reversal of 870120891657 is 756198021078.

870120891657 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 870120891657 - 2³ = 870120891649 is a prime.

It is a super-2 number, since 2×870120891657² (a number of 25 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (870120891697) 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, 44997363 + ... + 45016695.

It is an arithmetic number, because the mean of its divisors is an integer number (21576744000).

Almost surely, 2^870120891657 is an apocalyptic number.

It is an amenable number.

870120891657 is a deficient number, since it is larger than the sum of its proper divisors (510790724343).

870120891657 is a wasteful number, since it uses less digits than its factorization.

870120891657 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20907 (or 20901 counting only the distinct ones).

The product of its (nonzero) digits is 1693440, while the sum is 54.

The spelling of 870120891657 in words is "eight hundred seventy billion, one hundred twenty million, eight hundred ninety-one thousand, six hundred fifty-seven".