991297920006 has 40 divisors (see below), whose sum is σ = 2232871242624. Its totient is φ = 328702615920.

The previous prime is 991297919959. The next prime is 991297920047. The reversal of 991297920006 is 600029792199.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a congruent number.

It is an unprimeable number.

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 19 ways as a sum of consecutive naturals, for example, 15987705 + ... + 16049588.

Almost surely, 2^991297920006 is an apocalyptic number.

991297920006 is an abundant number, since it is smaller than the sum of its proper divisors (1241573322618).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

991297920006 is a wasteful number, since it uses less digits than its factorization.

991297920006 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32037498 (or 32037489 counting only the distinct ones).

The product of its (nonzero) digits is 1102248, while the sum is 54.

The spelling of 991297920006 in words is "nine hundred ninety-one billion, two hundred ninety-seven million, nine hundred twenty thousand, six".