39897864 has 24 divisors (see below), whose sum is σ = 108056910. Its totient is φ = 13299264.

The previous prime is 39897863. The next prime is 39897883. The reversal of 39897864 is 46879893.

It can be written as a sum of positive squares in only one way, i.e., 32832900 + 7064964 = 5730^2 + 2658^2 .

It is a tau number, because it is divible by the number of its divisors (24).

It is a self number, because there is not a number n which added to its sum of digits gives 39897864.

It is not an unprimeable number, because it can be changed into a prime (39897863) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 276997 + ... + 277140.

Almost surely, 2^39897864 is an apocalyptic number.

It is an amenable number.

39897864 is an abundant number, since it is smaller than the sum of its proper divisors (68159046).

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

39897864 is a wasteful number, since it uses less digits than its factorization.

39897864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 554149 (or 554142 counting only the distinct ones).

The product of its digits is 2612736, while the sum is 54.

The square root of 39897864 is about 6316.4755995729. The cubic root of 39897864 is about 341.7038577269.

The spelling of 39897864 in words is "thirty-nine million, eight hundred ninety-seven thousand, eight hundred sixty-four".