39942431 has 4 divisors (see below), whose sum is σ = 40048200. Its totient is φ = 39836664.

The previous prime is 39942379. The next prime is 39942439. The reversal of 39942431 is 13424993.

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

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-39942431 is a prime.

It is a super-2 number, since 2×39942431² = 3190795588379522, 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 = 39942391 and 39942400.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (39942439) 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, 52316 + ... + 53073.

It is an arithmetic number, because the mean of its divisors is an integer number (10012050).

Almost surely, 2^39942431 is an apocalyptic number.

39942431 is a deficient number, since it is larger than the sum of its proper divisors (105769).

39942431 is a wasteful number, since it uses less digits than its factorization.

39942431 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 105768.

The product of its digits is 23328, while the sum is 35.

The square root of 39942431 is about 6320.0024525312. The cubic root of 39942431 is about 341.8310412193.

The spelling of 39942431 in words is "thirty-nine million, nine hundred forty-two thousand, four hundred thirty-one".