664948917136 has 45 divisors (see below), whose sum is σ = 1498730973051. Its totient is φ = 284968322016.

The previous prime is 664948917133. The next prime is 664948917137. The reversal of 664948917136 is 631719849466.

The square root of 664948917136 is 815444.

It is a perfect power (a square), and thus also a powerful number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (664948917133) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 22817871 + ... + 22846993.

Almost surely, 2^664948917136 is an apocalyptic number.

664948917136 is the 815444-th square number.

It is an amenable number.

664948917136 is an abundant number, since it is smaller than the sum of its proper divisors (833782055915).

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

664948917136 is an frugal number, since it uses more digits than its factorization.

664948917136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 58268 (or 29132 counting only the distinct ones).

The product of its digits is 47029248, while the sum is 64.

Multiplying 664948917136 by its sum of digits (64), we get a square (42556730696704 = 6523552²).

The spelling of 664948917136 in words is "six hundred sixty-four billion, nine hundred forty-eight million, nine hundred seventeen thousand, one hundred thirty-six".