91020993 has 16 divisors (see below), whose sum is σ = 139554816. Its totient is φ = 51690960.

The previous prime is 91020989. The next prime is 91021013. The reversal of 91020993 is 39902019.

It is not a de Polignac number, because 91020993 - 2² = 91020989 is a prime.

It is not an unprimeable number, because it can be changed into a prime (91020973) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9873 + ... + 16718.

It is an arithmetic number, because the mean of its divisors is an integer number (8722176).

Almost surely, 2^91020993 is an apocalyptic number.

It is an amenable number.

91020993 is a deficient number, since it is larger than the sum of its proper divisors (48533823).

91020993 is a wasteful number, since it uses less digits than its factorization.

91020993 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 26764.

The product of its (nonzero) digits is 4374, while the sum is 33.

The square root of 91020993 is about 9540.4922828961. The cubic root of 91020993 is about 449.8287298845.

The spelling of 91020993 in words is "ninety-one million, twenty thousand, nine hundred ninety-three".