39031921 has 4 divisors (see below), whose sum is σ = 39096832. Its totient is φ = 38967012.

The previous prime is 39031907. The next prime is 39031933. The reversal of 39031921 is 12913093.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 39031921 - 2²³ = 30643313 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 39031921.

It is not an unprimeable number, because it can be changed into a prime (39031901) 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, 31545 + ... + 32758.

It is an arithmetic number, because the mean of its divisors is an integer number (9774208).

Almost surely, 2^39031921 is an apocalyptic number.

It is an amenable number.

39031921 is a deficient number, since it is larger than the sum of its proper divisors (64911).

39031921 is an equidigital number, since it uses as much as digits as its factorization.

39031921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64910.

The product of its (nonzero) digits is 1458, while the sum is 28.

The square root of 39031921 is about 6247.5532010540. The cubic root of 39031921 is about 339.2136411731.

The spelling of 39031921 in words is "thirty-nine million, thirty-one thousand, nine hundred twenty-one".