657125820 has 144 divisors (see below), whose sum is σ = 2273019840. Its totient is φ = 152229888.

The previous prime is 657125797. The next prime is 657125863. The reversal of 657125820 is 28521756.

It is a happy number.

657125820 is a `hidden beast` number, since 6 + 5 + 71 + 2 + 582 + 0 = 666.

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

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 31521 + ... + 48039.

It is an arithmetic number, because the mean of its divisors is an integer number (15784860).

Almost surely, 2^657125820 is an apocalyptic number.

657125820 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 657125820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1136509920).

657125820 is an abundant number, since it is smaller than the sum of its proper divisors (1615894020).

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

657125820 is a wasteful number, since it uses less digits than its factorization.

657125820 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16564 (or 16559 counting only the distinct ones).

The product of its (nonzero) digits is 33600, while the sum is 36.

The square root of 657125820 is about 25634.4654713142. The cubic root of 657125820 is about 869.3930765024.

The spelling of 657125820 in words is "six hundred fifty-seven million, one hundred twenty-five thousand, eight hundred twenty".