91039979 has 8 divisors (see below), whose sum is σ = 92494080. Its totient is φ = 89591616.

The previous prime is 91039933. The next prime is 91039997. The reversal of 91039979 is 97993019.

It is a happy number.

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 91039979 - 2⁸ = 91039723 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91039909) 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, 39542 + ... + 41780.

It is an arithmetic number, because the mean of its divisors is an integer number (11561760).

Almost surely, 2^91039979 is an apocalyptic number.

91039979 is a deficient number, since it is larger than the sum of its proper divisors (1454101).

91039979 is a wasteful number, since it uses less digits than its factorization.

91039979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2869.

The product of its (nonzero) digits is 137781, while the sum is 47.

The square root of 91039979 is about 9541.4872530439. The cubic root of 91039979 is about 449.8600041882.

The spelling of 91039979 in words is "ninety-one million, thirty-nine thousand, nine hundred seventy-nine".