646522920 has 192 divisors, whose sum is σ = 2242890000. Its totient is φ = 160948224.

The previous prime is 646522913. The next prime is 646522969. The reversal of 646522920 is 29225646.

646522920 is a `hidden beast` number, since 6 + 46 + 522 + 92 + 0 = 666.

It can be written as a sum of positive squares in 8 ways, for example, as 116510436 + 530012484 = 10794^2 + 23022^2 .

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

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 911526 + ... + 912234.

Almost surely, 2^646522920 is an apocalyptic number.

646522920 is a gapful number since it is divisible by the number (60) 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 646522920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1121445000).

646522920 is an abundant number, since it is smaller than the sum of its proper divisors (1596367080).

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

646522920 is a wasteful number, since it uses less digits than its factorization.

646522920 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 892 (or 885 counting only the distinct ones).

The product of its (nonzero) digits is 51840, while the sum is 36.

The square root of 646522920 is about 25426.8149794661. The cubic root of 646522920 is about 864.6917364143.

The spelling of 646522920 in words is "six hundred forty-six million, five hundred twenty-two thousand, nine hundred twenty".