916521840 has 120 divisors (see below), whose sum is σ = 3314787840. Its totient is φ = 225603072.

The previous prime is 916521817. The next prime is 916521847. The reversal of 916521840 is 48125619.

916521840 is a `hidden beast` number, since 91 + 6 + 521 + 8 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (120).

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

It is a junction number, because it is equal to n+sod(n) for n = 916521795 and 916521804.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (916521847) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 39600 + ... + 58319.

It is an arithmetic number, because the mean of its divisors is an integer number (27623232).

Almost surely, 2^916521840 is an apocalyptic number.

916521840 is a gapful number since it is divisible by the number (90) formed by its first and last digit.

It is an amenable number.

916521840 is an abundant number, since it is smaller than the sum of its proper divisors (2398266000).

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

916521840 is a wasteful number, since it uses less digits than its factorization.

916521840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 97951 (or 97942 counting only the distinct ones).

The product of its (nonzero) digits is 17280, while the sum is 36.

The square root of 916521840 is about 30274.1117128150. Note that the first 3 decimals coincide. The cubic root of 916521840 is about 971.3616191293.

The spelling of 916521840 in words is "nine hundred sixteen million, five hundred twenty-one thousand, eight hundred forty".