99906521857 has 4 divisors (see below), whose sum is σ = 100259548720. Its totient is φ = 99553494996.

The previous prime is 99906521831. The next prime is 99906521863. The reversal of 99906521857 is 75812560999.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 99906521857 - 2²⁷ = 99772304129 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 99906521795 and 99906521804.

It is not an unprimeable number, because it can be changed into a prime (99906521807) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 176513007 + ... + 176513572.

It is an arithmetic number, because the mean of its divisors is an integer number (25064887180).

Almost surely, 2^99906521857 is an apocalyptic number.

It is an amenable number.

99906521857 is a deficient number, since it is larger than the sum of its proper divisors (353026863).

99906521857 is a wasteful number, since it uses less digits than its factorization.

99906521857 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 353026862.

The product of its (nonzero) digits is 12247200, while the sum is 61.

The spelling of 99906521857 in words is "ninety-nine billion, nine hundred six million, five hundred twenty-one thousand, eight hundred fifty-seven".