91015679 has 4 divisors (see below), whose sum is σ = 91221576. Its totient is φ = 90809784.

The previous prime is 91015657. The next prime is 91015697. The reversal of 91015679 is 97651019.

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

It is a cyclic number.

It is not a de Polignac number, because 91015679 - 2¹⁶ = 90950143 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91017679) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 102284 + ... + 103169.

It is an arithmetic number, because the mean of its divisors is an integer number (22805394).

Almost surely, 2^91015679 is an apocalyptic number.

91015679 is a deficient number, since it is larger than the sum of its proper divisors (205897).

91015679 is a wasteful number, since it uses less digits than its factorization.

91015679 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 205896.

The product of its (nonzero) digits is 17010, while the sum is 38.

The square root of 91015679 is about 9540.2137816718. The cubic root of 91015679 is about 449.8199757268.

The spelling of 91015679 in words is "ninety-one million, fifteen thousand, six hundred seventy-nine".