664616740 has 24 divisors (see below), whose sum is σ = 1456378560. Its totient is φ = 254287968.

The previous prime is 664616737. The next prime is 664616749. The reversal of 664616740 is 47616466.

It is a happy number.

It is a super-2 number, since 2×664616740² = 883430822176455200, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 664616693 and 664616702.

It is not an unprimeable number, because it can be changed into a prime (664616749) by changing a digit.

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 7 ways as a sum of consecutive naturals, for example, 721950 + ... + 722869.

It is an arithmetic number, because the mean of its divisors is an integer number (60682440).

Almost surely, 2^664616740 is an apocalyptic number.

It is an amenable number.

664616740 is an abundant number, since it is smaller than the sum of its proper divisors (791761820).

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

664616740 is a wasteful number, since it uses less digits than its factorization.

664616740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1444851 (or 1444849 counting only the distinct ones).

The product of its (nonzero) digits is 145152, while the sum is 40.

The square root of 664616740 is about 25780.1617527897. The cubic root of 664616740 is about 872.6841574804.

The spelling of 664616740 in words is "six hundred sixty-four million, six hundred sixteen thousand, seven hundred forty".