39664961 has 18 divisors (see below), whose sum is σ = 49032198. Its totient is φ = 31987200.

The previous prime is 39664957. The next prime is 39664969. The reversal of 39664961 is 16946693.

39664961 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 3 ways, for example, as 16200625 + 23464336 = 4025^2 + 4844^2 .

It is not a de Polignac number, because 39664961 - 2² = 39664957 is a prime.

It is a super-2 number, since 2×39664961² = 3146618262263042, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (39664969) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 12761 + ... + 15561.

It is an arithmetic number, because the mean of its divisors is an integer number (2724011).

Almost surely, 2^39664961 is an apocalyptic number.

It is an amenable number.

39664961 is a deficient number, since it is larger than the sum of its proper divisors (9367237).

39664961 is a wasteful number, since it uses less digits than its factorization.

39664961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2849 (or 2825 counting only the distinct ones).

The product of its digits is 209952, while the sum is 44.

The square root of 39664961 is about 6298.0124642620. The cubic root of 39664961 is about 341.0376632147.

The spelling of 39664961 in words is "thirty-nine million, six hundred sixty-four thousand, nine hundred sixty-one".