664581747756 has 24 divisors (see below), whose sum is σ = 1632306047680. Its totient is φ = 209867920272.

The previous prime is 664581747749. The next prime is 664581747757. The reversal of 664581747756 is 657747185466.

It is a super-2 number, since 2×664581747756² (a number of 24 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (664581747757) 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, 1457415886 + ... + 1457416341.

Almost surely, 2^664581747756 is an apocalyptic number.

It is an amenable number.

664581747756 is an abundant number, since it is smaller than the sum of its proper divisors (967724299924).

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

664581747756 is a wasteful number, since it uses less digits than its factorization.

664581747756 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2914832253 (or 2914832251 counting only the distinct ones).

The product of its digits is 237081600, while the sum is 66.

The spelling of 664581747756 in words is "six hundred sixty-four billion, five hundred eighty-one million, seven hundred forty-seven thousand, seven hundred fifty-six".