39904821 has 12 divisors (see below), whose sum is σ = 62880480. Its totient is φ = 24184680.

The previous prime is 39904819. The next prime is 39904829. The reversal of 39904821 is 12840993.

It is not a de Polignac number, because 39904821 - 2¹ = 39904819 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (39904829) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 201441 + ... + 201638.

It is an arithmetic number, because the mean of its divisors is an integer number (5240040).

Almost surely, 2^39904821 is an apocalyptic number.

It is an amenable number.

39904821 is a deficient number, since it is larger than the sum of its proper divisors (22975659).

39904821 is a wasteful number, since it uses less digits than its factorization.

39904821 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 403096 (or 403093 counting only the distinct ones).

The product of its (nonzero) digits is 15552, while the sum is 36.

The square root of 39904821 is about 6317.0262782420. The cubic root of 39904821 is about 341.7237175669.

The spelling of 39904821 in words is "thirty-nine million, nine hundred four thousand, eight hundred twenty-one".