99997100021 has 16 divisors (see below), whose sum is σ = 123080861568. Its totient is φ = 79113758400.

The previous prime is 99997100017. The next prime is 99997100029. The reversal of 99997100021 is 12000179999.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 99997100021 - 2² = 99997100017 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (99997100029) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2580731 + ... + 2619191.

It is an arithmetic number, because the mean of its divisors is an integer number (7692553848).

Almost surely, 2^99997100021 is an apocalyptic number.

99997100021 is a gapful number since it is divisible by the number (91) formed by its first and last digit.

It is an amenable number.

99997100021 is a deficient number, since it is larger than the sum of its proper divisors (23083761547).

99997100021 is a wasteful number, since it uses less digits than its factorization.

99997100021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 67052.

The product of its (nonzero) digits is 91854, while the sum is 47.

The spelling of 99997100021 in words is "ninety-nine billion, nine hundred ninety-seven million, one hundred thousand, twenty-one".