39921899 has 4 divisors (see below), whose sum is σ = 42270264. Its totient is φ = 37573536.

The previous prime is 39921881. The next prime is 39921911. The reversal of 39921899 is 99812993.

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

It is not a de Polignac number, because 39921899 - 2⁸ = 39921643 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (39921839) 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, 1174157 + ... + 1174190.

It is an arithmetic number, because the mean of its divisors is an integer number (10567566).

Almost surely, 2^39921899 is an apocalyptic number.

39921899 is a deficient number, since it is larger than the sum of its proper divisors (2348365).

39921899 is a wasteful number, since it uses less digits than its factorization.

39921899 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2348364.

The product of its digits is 314928, while the sum is 50.

The square root of 39921899 is about 6318.3778772720. The cubic root of 39921899 is about 341.7724595916.

The spelling of 39921899 in words is "thirty-nine million, nine hundred twenty-one thousand, eight hundred ninety-nine".