99521172065501 has 4 divisors (see below), whose sum is σ = 99521205693504. Its totient is φ = 99521138437500.

The previous prime is 99521172065477. The next prime is 99521172065593. The reversal of 99521172065501 is 10556027112599.

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 a de Polignac number, because none of the positive numbers 2^k-99521172065501 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99521172365501) 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, 11895125 + ... + 18453626.

It is an arithmetic number, because the mean of its divisors is an integer number (24880301423376).

Almost surely, 2^{99521172065501} is an apocalyptic number.

It is an amenable number.

99521172065501 is a deficient number, since it is larger than the sum of its proper divisors (33628003).

99521172065501 is a wasteful number, since it uses less digits than its factorization.

99521172065501 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33628002.

The product of its (nonzero) digits is 1701000, while the sum is 53.

The spelling of 99521172065501 in words is "ninety-nine trillion, five hundred twenty-one billion, one hundred seventy-two million, sixty-five thousand, five hundred one".