90812640 has 192 divisors, whose sum is σ = 313528320. Its totient is φ = 21995520.

The previous prime is 90812597. The next prime is 90812641. The reversal of 90812640 is 4621809.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a junction number, because it is equal to n+sod(n) for n = 90812598 and 90812607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (90812641) 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, 252781 + ... + 253139.

It is an arithmetic number, because the mean of its divisors is an integer number (1632960).

Almost surely, 2^90812640 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 90812640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (156764160).

90812640 is an abundant number, since it is smaller than the sum of its proper divisors (222715680).

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

90812640 is a wasteful number, since it uses less digits than its factorization.

90812640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 425 (or 417 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 30.

The square root of 90812640 is about 9529.5666218354. The cubic root of 90812640 is about 449.4852385420.

The spelling of 90812640 in words is "ninety million, eight hundred twelve thousand, six hundred forty".