664655540 has 12 divisors (see below), whose sum is σ = 1395776676. Its totient is φ = 265862208.

The previous prime is 664655539. The next prime is 664655561. The reversal of 664655540 is 45556466.

It can be written as a sum of positive squares in 2 ways, for example, as 325874704 + 338780836 = 18052^2 + 18406^2 .

It is a hoax number, since the sum of its digits (41) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 16616369 + ... + 16616408.

It is an arithmetic number, because the mean of its divisors is an integer number (116314723).

Almost surely, 2^664655540 is an apocalyptic number.

It is an amenable number.

664655540 is an abundant number, since it is smaller than the sum of its proper divisors (731121136).

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

664655540 is a wasteful number, since it uses less digits than its factorization.

664655540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 33232786 (or 33232784 counting only the distinct ones).

The product of its (nonzero) digits is 432000, while the sum is 41.

The square root of 664655540 is about 25780.9142584199. The cubic root of 664655540 is about 872.7011394413.

The spelling of 664655540 in words is "six hundred sixty-four million, six hundred fifty-five thousand, five hundred forty".