878138521850557 has 32 divisors (see below), whose sum is σ = 1025613276624000. Its totient is φ = 743471381283840.

The previous prime is 878138521850531. The next prime is 878138521850599. The reversal of 878138521850557 is 755058125831878.

It is a happy number.

It is a de Polignac number, because none of the positive numbers 2^k-878138521850557 is a prime.

It is a super-2 number, since 2×878138521850557² (a number of 31 digits) contains 22 as substring.

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 878138521850557.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (878138521850507) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 133224832 + ... + 139660777.

It is an arithmetic number, because the mean of its divisors is an integer number (32050414894500).

Almost surely, 2^{878138521850557} is an apocalyptic number.

It is an amenable number.

878138521850557 is a deficient number, since it is larger than the sum of its proper divisors (147474754773443).

878138521850557 is a wasteful number, since it uses less digits than its factorization.

878138521850557 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 272885901.

The product of its (nonzero) digits is 752640000, while the sum is 73.

The spelling of 878138521850557 in words is "eight hundred seventy-eight trillion, one hundred thirty-eight billion, five hundred twenty-one million, eight hundred fifty thousand, five hundred fifty-seven".