91839917890 has 16 divisors (see below), whose sum is σ = 188927831232. Its totient is φ = 31487971824.

The previous prime is 91839917879. The next prime is 91839917899. The reversal of 91839917890 is 9871993819.

It is not an unprimeable number, because it can be changed into a prime (91839917899) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 655999344 + ... + 655999483.

It is an arithmetic number, because the mean of its divisors is an integer number (11807989452).

Almost surely, 2^91839917890 is an apocalyptic number.

91839917890 is an abundant number, since it is smaller than the sum of its proper divisors (97087913342).

91839917890 is a wasteful number, since it uses less digits than its factorization.

91839917890 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1311998841.

The product of its (nonzero) digits is 8817984, while the sum is 64.

The spelling of 91839917890 in words is "ninety-one billion, eight hundred thirty-nine million, nine hundred seventeen thousand, eight hundred ninety".