39193921 has 8 divisors (see below), whose sum is σ = 42444584. Its totient is φ = 35976960.

The previous prime is 39193907. The next prime is 39193927. The reversal of 39193921 is 12939193.

It can be written as a sum of positive squares in 4 ways, for example, as 1849600 + 37344321 = 1360^2 + 6111^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 39193921 - 2⁷ = 39193793 is a prime.

It is not an unprimeable number, because it can be changed into a prime (39193927) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5976 + ... + 10681.

It is an arithmetic number, because the mean of its divisors is an integer number (5305573).

Almost surely, 2^39193921 is an apocalyptic number.

It is an amenable number.

39193921 is a deficient number, since it is larger than the sum of its proper divisors (3250663).

39193921 is a wasteful number, since it uses less digits than its factorization.

39193921 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 16851.

The product of its digits is 13122, while the sum is 37.

The square root of 39193921 is about 6260.5048518470. The cubic root of 39193921 is about 339.6822897158.

The spelling of 39193921 in words is "thirty-nine million, one hundred ninety-three thousand, nine hundred twenty-one".