91012421008 has 80 divisors (see below), whose sum is σ = 189475038000. Its totient is φ = 42344890368.

The previous prime is 91012420969. The next prime is 91012421011. The reversal of 91012421008 is 80012421019.

It can be written as a sum of positive squares in 8 ways, for example, as 6791737744 + 84220683264 = 82412^2 + 290208^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 6989608 + ... + 7002616.

It is an arithmetic number, because the mean of its divisors is an integer number (2368437975).

Almost surely, 2^91012421008 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 91012421008, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (94737519000).

91012421008 is an abundant number, since it is smaller than the sum of its proper divisors (98462616992).

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

91012421008 is a wasteful number, since it uses less digits than its factorization.

91012421008 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13157 (or 13117 counting only the distinct ones).

The product of its (nonzero) digits is 1152, while the sum is 28.

The spelling of 91012421008 in words is "ninety-one billion, twelve million, four hundred twenty-one thousand, eight".