91007979 has 4 divisors (see below), whose sum is σ = 121343976. Its totient is φ = 60671984.

The previous prime is 91007977. The next prime is 91007981. The reversal of 91007979 is 97970019.

It is a semiprime because it is the product of two primes.

It is an interprime number because it is at equal distance from previous prime (91007977) and next prime (91007981).

It is a cyclic number.

It is not a de Polignac number, because 91007979 - 2¹ = 91007977 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 91007979.

It is not an unprimeable number, because it can be changed into a prime (91007977) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 15167994 + ... + 15167999.

It is an arithmetic number, because the mean of its divisors is an integer number (30335994).

Almost surely, 2^91007979 is an apocalyptic number.

91007979 is a deficient number, since it is larger than the sum of its proper divisors (30335997).

91007979 is a wasteful number, since it uses less digits than its factorization.

91007979 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30335996.

The product of its (nonzero) digits is 35721, while the sum is 42.

The square root of 91007979 is about 9539.8102182381. The cubic root of 91007979 is about 449.8072903246.

The spelling of 91007979 in words is "ninety-one million, seven thousand, nine hundred seventy-nine".