39920391 has 16 divisors (see below), whose sum is σ = 67590400. Its totient is φ = 22811544.

The previous prime is 39920381. The next prime is 39920393. The reversal of 39920391 is 19302993.

It is not a de Polignac number, because 39920391 - 2⁹ = 39919879 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (39920393) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 105421 + ... + 105798.

It is an arithmetic number, because the mean of its divisors is an integer number (4224400).

Almost surely, 2^39920391 is an apocalyptic number.

39920391 is a deficient number, since it is larger than the sum of its proper divisors (27670009).

39920391 is a wasteful number, since it uses less digits than its factorization.

39920391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 211235 (or 211229 counting only the distinct ones).

The product of its (nonzero) digits is 13122, while the sum is 36.

The square root of 39920391 is about 6318.2585417186. The cubic root of 39920391 is about 341.7681561944.

The spelling of 39920391 in words is "thirty-nine million, nine hundred twenty thousand, three hundred ninety-one".