91040785921 has 8 divisors (see below), whose sum is σ = 91260808064. Its totient is φ = 90820865520.

The previous prime is 91040785919. The next prime is 91040785949. The reversal of 91040785921 is 12958704019.

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 91040785921 - 2¹ = 91040785919 is a prime.

It is a super-2 number, since 2×91040785921² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (91040785951) 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, 1949770 + ... + 1995916.

It is an arithmetic number, because the mean of its divisors is an integer number (11407601008).

Almost surely, 2^91040785921 is an apocalyptic number.

It is an amenable number.

91040785921 is a deficient number, since it is larger than the sum of its proper divisors (220022143).

91040785921 is a wasteful number, since it uses less digits than its factorization.

91040785921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 50871.

The product of its (nonzero) digits is 181440, while the sum is 46.

The spelling of 91040785921 in words is "ninety-one billion, forty million, seven hundred eighty-five thousand, nine hundred twenty-one".