657385879640 has 96 divisors (see below), whose sum is σ = 1721066285520. Its totient is φ = 225329271552.

The previous prime is 657385879607. The next prime is 657385879691. The reversal of 657385879640 is 46978583756.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7634507 + ... + 7720133.

Almost surely, 2^657385879640 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 657385879640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (860533142760).

657385879640 is an abundant number, since it is smaller than the sum of its proper divisors (1063680405880).

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

657385879640 is a wasteful number, since it uses less digits than its factorization.

657385879640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 89569 (or 89558 counting only the distinct ones).

The product of its (nonzero) digits is 304819200, while the sum is 68.

The spelling of 657385879640 in words is "six hundred fifty-seven billion, three hundred eighty-five million, eight hundred seventy-nine thousand, six hundred forty".