91990080000 has 1800 divisors, whose sum is σ = 425764186848. Its totient is φ = 19408896000.

The previous prime is 91990079999. The next prime is 91990080029. The reversal of 91990080000 is 8009919.

It is a tau number, because it is divible by the number of its divisors (1800).

It is a Harshad number since it is a multiple of its sum of digits (36).

It is an unprimeable number.

It is a polite number, since it can be written in 179 ways as a sum of consecutive naturals, for example, 7076159994 + ... + 7076160006.

Almost surely, 2^91990080000 is an apocalyptic number.

91990080000 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 91990080000, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (212882093424).

91990080000 is an abundant number, since it is smaller than the sum of its proper divisors (333774106848).

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

91990080000 is an frugal number, since it uses more digits than its factorization.

91990080000 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 86 (or 30 counting only the distinct ones).

The product of its (nonzero) digits is 5832, while the sum is 36.

Adding to 91990080000 its reverse (8009919), we get a palindrome (91998089919).

The spelling of 91990080000 in words is "ninety-one billion, nine hundred ninety million, eighty thousand".