91031979 has 8 divisors (see below), whose sum is σ = 122262480. Its totient is φ = 60244736.

The previous prime is 91031977. The next prime is 91031987. The reversal of 91031979 is 97913019.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 91031979 - 2¹ = 91031977 is a prime.

It is not an unprimeable number, because it can be changed into a prime (91031971) 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, 110334 + ... + 111155.

It is an arithmetic number, because the mean of its divisors is an integer number (15282810).

Almost surely, 2^91031979 is an apocalyptic number.

91031979 is a deficient number, since it is larger than the sum of its proper divisors (31230501).

91031979 is a wasteful number, since it uses less digits than its factorization.

91031979 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 221629.

The product of its (nonzero) digits is 15309, while the sum is 39.

The square root of 91031979 is about 9541.0680219774. The cubic root of 91031979 is about 449.8468268805.

The spelling of 91031979 in words is "ninety-one million, thirty-one thousand, nine hundred seventy-nine".