39249921 has 4 divisors (see below), whose sum is σ = 52333232. Its totient is φ = 26166612.

The previous prime is 39249893. The next prime is 39249929. The reversal of 39249921 is 12994293.

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 not a de Polignac number, because 39249921 - 2¹⁵ = 39217153 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 39249921.

It is not an unprimeable number, because it can be changed into a prime (39249929) 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, 6541651 + ... + 6541656.

It is an arithmetic number, because the mean of its divisors is an integer number (13083308).

Almost surely, 2^39249921 is an apocalyptic number.

It is an amenable number.

39249921 is a deficient number, since it is larger than the sum of its proper divisors (13083311).

39249921 is a wasteful number, since it uses less digits than its factorization.

39249921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13083310.

The product of its digits is 34992, while the sum is 39.

The square root of 39249921 is about 6264.9757381813. The cubic root of 39249921 is about 339.8439912869.

The spelling of 39249921 in words is "thirty-nine million, two hundred forty-nine thousand, nine hundred twenty-one".