99909990997 has 4 divisors (see below), whose sum is σ = 100672662816. Its totient is φ = 99147319180.

The previous prime is 99909990989. The next prime is 99909991007. The reversal of 99909990997 is 79909990999.

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, and also an emirpimes, since its reverse is a distinct semiprime: 79909990999 = 29 ⋅2755516931.

It is a cyclic number.

It is not a de Polignac number, because 99909990997 - 2³ = 99909990989 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 (99909990977) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 381335713 + ... + 381335974.

It is an arithmetic number, because the mean of its divisors is an integer number (25168165704).

Almost surely, 2^99909990997 is an apocalyptic number.

It is an amenable number.

99909990997 is a deficient number, since it is larger than the sum of its proper divisors (762671819).

99909990997 is a wasteful number, since it uses less digits than its factorization.

99909990997 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 762671818.

The product of its (nonzero) digits is 301327047, while the sum is 79.

The spelling of 99909990997 in words is "ninety-nine billion, nine hundred nine million, nine hundred ninety thousand, nine hundred ninety-seven".