39920431 has 4 divisors (see below), whose sum is σ = 40308112. Its totient is φ = 39532752.

The previous prime is 39920423. The next prime is 39920477. The reversal of 39920431 is 13402993.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 39920431 - 2³ = 39920423 is a prime.

It is a super-2 number, since 2×39920431² = 3187281622451522, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 39920393 and 39920402.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (39920411) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 193686 + ... + 193891.

It is an arithmetic number, because the mean of its divisors is an integer number (10077028).

Almost surely, 2^39920431 is an apocalyptic number.

39920431 is a deficient number, since it is larger than the sum of its proper divisors (387681).

39920431 is a wasteful number, since it uses less digits than its factorization.

39920431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 387680.

The product of its (nonzero) digits is 5832, while the sum is 31.

The square root of 39920431 is about 6318.2617071470. The cubic root of 39920431 is about 341.7682703443.

The spelling of 39920431 in words is "thirty-nine million, nine hundred twenty thousand, four hundred thirty-one".