91638856703940 has 1152 divisors, whose sum is σ = 350792763310080. Its totient is φ = 17649205862400.

The previous prime is 91638856703939. The next prime is 91638856703951. The reversal of 91638856703940 is 4930765883619.

It is an unprimeable number.

It is a polite number, since it can be written in 383 ways as a sum of consecutive naturals, for example, 5245189405 + ... + 5245206875.

It is an arithmetic number, because the mean of its divisors is an integer number (304507607040).

Almost surely, 2^{91638856703940} is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91638856703940, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (175396381655040).

91638856703940 is an abundant number, since it is smaller than the sum of its proper divisors (259153906606140).

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

91638856703940 is a wasteful number, since it uses less digits than its factorization.

91638856703940 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17793 (or 17784 counting only the distinct ones).

The product of its (nonzero) digits is 235146240, while the sum is 69.

The spelling of 91638856703940 in words is "ninety-one trillion, six hundred thirty-eight billion, eight hundred fifty-six million, seven hundred three thousand, nine hundred forty".