657638790660 has 36 divisors (see below), whose sum is σ = 1994837665548. Its totient is φ = 175370344128.

The previous prime is 657638790637. The next prime is 657638790737. The reversal of 657638790660 is 66097836756.

It can be written as a sum of positive squares in 2 ways, for example, as 342533949696 + 315104840964 = 585264^2 + 561342^2 .

It is a tau number, because it is divible by the number of its divisors (36).

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 11 ways as a sum of consecutive naturals, for example, 1826774239 + ... + 1826774598.

Almost surely, 2^657638790660 is an apocalyptic number.

657638790660 is a gapful number since it is divisible by the number (60) formed by its first and last digit.

It is an amenable number.

657638790660 is an abundant number, since it is smaller than the sum of its proper divisors (1337198874888).

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

657638790660 is a wasteful number, since it uses less digits than its factorization.

657638790660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3653548852 (or 3653548847 counting only the distinct ones).

The product of its (nonzero) digits is 68584320, while the sum is 63.

The spelling of 657638790660 in words is "six hundred fifty-seven billion, six hundred thirty-eight million, seven hundred ninety thousand, six hundred sixty".