39905664 has 64 divisors (see below), whose sum is σ = 112253040. Its totient is φ = 12517376.

The previous prime is 39905659. The next prime is 39905689. The reversal of 39905664 is 46650993.

It is a tau number, because it is divible by the number of its divisors (64).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3472 + ... + 9584.

Almost surely, 2^39905664 is an apocalyptic number.

39905664 is a gapful number since it is divisible by the number (34) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 39905664, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (56126520).

39905664 is an abundant number, since it is smaller than the sum of its proper divisors (72347376).

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

39905664 is a wasteful number, since it uses less digits than its factorization.

39905664 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6147 (or 6135 counting only the distinct ones).

The product of its (nonzero) digits is 174960, while the sum is 42.

The square root of 39905664 is about 6317.0930023231. The cubic root of 39905664 is about 341.7261238849.

The spelling of 39905664 in words is "thirty-nine million, nine hundred five thousand, six hundred sixty-four".