99621724578121 has 16 divisors (see below), whose sum is σ = 100594265486400. Its totient is φ = 98652978632448.

The previous prime is 99621724578113. The next prime is 99621724578169. The reversal of 99621724578121 is 12187542712699.

It is a cyclic number.

It is not a de Polignac number, because 99621724578121 - 2³ = 99621724578113 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (99621794578121) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 113295466 + ... + 114171388.

It is an arithmetic number, because the mean of its divisors is an integer number (6287141592900).

Almost surely, 2^{99621724578121} is an apocalyptic number.

It is an amenable number.

99621724578121 is a deficient number, since it is larger than the sum of its proper divisors (972540908279).

99621724578121 is a wasteful number, since it uses less digits than its factorization.

99621724578121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 878088.

The product of its digits is 30481920, while the sum is 64.

The spelling of 99621724578121 in words is "ninety-nine trillion, six hundred twenty-one billion, seven hundred twenty-four million, five hundred seventy-eight thousand, one hundred twenty-one".