91432897920 has 1536 divisors, whose sum is σ = 426003701760. Its totient is φ = 17517772800.

The previous prime is 91432897849. The next prime is 91432897939. The reversal of 91432897920 is 2979823419.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 276232155 + ... + 276232485.

It is an arithmetic number, because the mean of its divisors is an integer number (277346160).

Almost surely, 2^91432897920 is an apocalyptic number.

91432897920 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 91432897920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (213001850880).

91432897920 is an abundant number, since it is smaller than the sum of its proper divisors (334570803840).

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

91432897920 is a wasteful number, since it uses less digits than its factorization.

91432897920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 424 (or 409 counting only the distinct ones).

The product of its (nonzero) digits is 1959552, while the sum is 54.

The spelling of 91432897920 in words is "ninety-one billion, four hundred thirty-two million, eight hundred ninety-seven thousand, nine hundred twenty".