91990400 has 192 divisors, whose sum is σ = 256122000. Its totient is φ = 32440320.

The previous prime is 91990321. The next prime is 91990411. The reversal of 91990400 is 409919.

It is a Harshad number since it is a multiple of its sum of digits (32).

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 1033556 + ... + 1033644.

Almost surely, 2^91990400 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 91990400, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (128061000).

91990400 is an abundant number, since it is smaller than the sum of its proper divisors (164131600).

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

91990400 is a wasteful number, since it uses less digits than its factorization.

91990400 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 149 (or 132 counting only the distinct ones).

The product of its (nonzero) digits is 2916, while the sum is 32.

The square root of 91990400 is about 9591.1625989762. The cubic root of 91990400 is about 451.4200408884.

It can be divided in two parts, 919 and 90400, that added together give a palindrome (91319).

The spelling of 91990400 in words is "ninety-one million, nine hundred ninety thousand, four hundred".