657138887 has 8 divisors (see below), whose sum is σ = 665240400. Its totient is φ = 649053504.

The previous prime is 657138847. The next prime is 657138917. The reversal of 657138887 is 788831756.

657138887 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 657138887 - 2²² = 652944583 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (657138847) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 91688 + ... + 98594.

It is an arithmetic number, because the mean of its divisors is an integer number (83155050).

Almost surely, 2^657138887 is an apocalyptic number.

657138887 is a deficient number, since it is larger than the sum of its proper divisors (8101513).

657138887 is a wasteful number, since it uses less digits than its factorization.

657138887 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8065.

The product of its digits is 2257920, while the sum is 53.

The square root of 657138887 is about 25634.7203417552. The cubic root of 657138887 is about 869.3988391147.

The spelling of 657138887 in words is "six hundred fifty-seven million, one hundred thirty-eight thousand, eight hundred eighty-seven".