657387990 has 96 divisors (see below), whose sum is σ = 1967696640. Its totient is φ = 149159232.

The previous prime is 657387989. The next prime is 657388019. The reversal of 657387990 is 99783756.

657387990 is digitally balanced in base 6, because in such base it contains all the possibile digits an equal number of times.

It is a congruent number.

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, 83817 + ... + 91323.

It is an arithmetic number, because the mean of its divisors is an integer number (20496840).

Almost surely, 2^657387990 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 657387990, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (983848320).

657387990 is an abundant number, since it is smaller than the sum of its proper divisors (1310308650).

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

657387990 is a wasteful number, since it uses less digits than its factorization.

657387990 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7666 (or 7663 counting only the distinct ones).

The product of its (nonzero) digits is 2857680, while the sum is 54.

The square root of 657387990 is about 25639.5785846804. The cubic root of 657387990 is about 869.5086801767.

The spelling of 657387990 in words is "six hundred fifty-seven million, three hundred eighty-seven thousand, nine hundred ninety".