91357782420 has 24 divisors (see below), whose sum is σ = 255801790944. Its totient is φ = 24362075296.

The previous prime is 91357782407. The next prime is 91357782443. The reversal of 91357782420 is 2428775319.

It is a happy number.

It is a super-2 number, since 2×91357782420² (a number of 23 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 91357782420.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 761314794 + ... + 761314913.

It is an arithmetic number, because the mean of its divisors is an integer number (10658407956).

Almost surely, 2^91357782420 is an apocalyptic number.

It is an amenable number.

91357782420 is an abundant number, since it is smaller than the sum of its proper divisors (164444008524).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

91357782420 is a wasteful number, since it uses less digits than its factorization.

91357782420 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1522629719 (or 1522629717 counting only the distinct ones).

The product of its (nonzero) digits is 846720, while the sum is 48.

The spelling of 91357782420 in words is "ninety-one billion, three hundred fifty-seven million, seven hundred eighty-two thousand, four hundred twenty".