91009256291 has 4 divisors (see below), whose sum is σ = 93945038784. Its totient is φ = 88073473800.

The previous prime is 91009256269. The next prime is 91009256363. The reversal of 91009256291 is 19265290019.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 19265290019 = 127 ⋅151695197.

It is a de Polignac number, because none of the positive numbers 2^k-91009256291 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91009256231) 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, 1467891200 + ... + 1467891261.

It is an arithmetic number, because the mean of its divisors is an integer number (23486259696).

Almost surely, 2^91009256291 is an apocalyptic number.

91009256291 is a deficient number, since it is larger than the sum of its proper divisors (2935782493).

91009256291 is a wasteful number, since it uses less digits than its factorization.

91009256291 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2935782492.

The product of its (nonzero) digits is 87480, while the sum is 44.

The spelling of 91009256291 in words is "ninety-one billion, nine million, two hundred fifty-six thousand, two hundred ninety-one".