39897664 has 14 divisors (see below), whose sum is σ = 79172054. Its totient is φ = 19948800.

The previous prime is 39897661. The next prime is 39897667. The reversal of 39897664 is 46679893.

It is an interprime number because it is at equal distance from previous prime (39897661) and next prime (39897667).

It can be written as a sum of positive squares in only one way, i.e., 33547264 + 6350400 = 5792^2 + 2520^2 .

It is not an unprimeable number, because it can be changed into a prime (39897661) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 311637 + ... + 311764.

Almost surely, 2^39897664 is an apocalyptic number.

It is an amenable number.

39897664 is a deficient number, since it is larger than the sum of its proper divisors (39274390).

39897664 is an equidigital number, since it uses as much as digits as its factorization.

39897664 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 623413 (or 623403 counting only the distinct ones).

The product of its digits is 1959552, while the sum is 52.

The square root of 39897664 is about 6316.4597679396. The cubic root of 39897664 is about 341.7032867617.

The spelling of 39897664 in words is "thirty-nine million, eight hundred ninety-seven thousand, six hundred sixty-four".