657138258 has 80 divisors (see below), whose sum is σ = 1694007744. Its totient is φ = 186507360.

The previous prime is 657138239. The next prime is 657138269. The reversal of 657138258 is 852831756.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 176193 + ... + 179883.

Almost surely, 2^657138258 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 657138258, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (847003872).

657138258 is an abundant number, since it is smaller than the sum of its proper divisors (1036869486).

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

657138258 is a wasteful number, since it uses less digits than its factorization.

657138258 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3869 (or 3860 counting only the distinct ones).

The product of its digits is 403200, while the sum is 45.

The square root of 657138258 is about 25634.7080732354. The cubic root of 657138258 is about 869.3985617243.

The spelling of 657138258 in words is "six hundred fifty-seven million, one hundred thirty-eight thousand, two hundred fifty-eight".