991473285099 has 32 divisors (see below), whose sum is σ = 1528915827456. Its totient is φ = 564827397120.

The previous prime is 991473285073. The next prime is 991473285149. The reversal of 991473285099 is 990582374199.

It is not a de Polignac number, because 991473285099 - 2²⁴ = 991456507883 is a prime.

It is a Smith number, since the sum of its digits (66) coincides with the sum of the digits of its prime factors. Since it is squarefree, it is also a hoax number.

It is not an unprimeable number, because it can be changed into a prime (991473285199) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 681322 + ... + 1564335.

It is an arithmetic number, because the mean of its divisors is an integer number (47778619608).

Almost surely, 2^991473285099 is an apocalyptic number.

991473285099 is a deficient number, since it is larger than the sum of its proper divisors (537442542357).

991473285099 is a wasteful number, since it uses less digits than its factorization.

991473285099 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2246475.

The product of its (nonzero) digits is 44089920, while the sum is 66.

The spelling of 991473285099 in words is "nine hundred ninety-one billion, four hundred seventy-three million, two hundred eighty-five thousand, ninety-nine".