91997783221120 has 128 divisors (see below), whose sum is σ = 251354859537600. Its totient is φ = 31541623603200.

The previous prime is 91997783221117. The next prime is 91997783221121. The reversal of 91997783221120 is 2112238779919.

It is a tau number, because it is divible by the number of its divisors (128).

It is a hoax number, since the sum of its digits (61) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91997783221121) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 436107670 + ... + 436318570.

Almost surely, 2^{91997783221120} is an apocalyptic number.

It is an amenable number.

91997783221120 is an abundant number, since it is smaller than the sum of its proper divisors (159357076316480).

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

91997783221120 is a wasteful number, since it uses less digits than its factorization.

91997783221120 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 308296 (or 308284 counting only the distinct ones).

The product of its (nonzero) digits is 6858432, while the sum is 61.

The spelling of 91997783221120 in words is "ninety-one trillion, nine hundred ninety-seven billion, seven hundred eighty-three million, two hundred twenty-one thousand, one hundred twenty".