91415520 has 192 divisors, whose sum is σ = 365783040. Its totient is φ = 20888064.

The previous prime is 91415507. The next prime is 91415521. The reversal of 91415520 is 2551419.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (91415521) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 28729 + ... + 31751.

It is an arithmetic number, because the mean of its divisors is an integer number (1905120).

Almost surely, 2^91415520 is an apocalyptic number.

91415520 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 91415520, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (182891520).

91415520 is an abundant number, since it is smaller than the sum of its proper divisors (274367520).

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

91415520 is a wasteful number, since it uses less digits than its factorization.

91415520 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3054 (or 3040 counting only the distinct ones).

The product of its (nonzero) digits is 1800, while the sum is 27.

The square root of 91415520 is about 9561.1463747816. The cubic root of 91415520 is about 450.4777149060.

Adding to 91415520 its reverse (2551419), we get a palindrome (93966939).

The spelling of 91415520 in words is "ninety-one million, four hundred fifteen thousand, five hundred twenty".