393939638 has 4 divisors (see below), whose sum is σ = 590909460. Its totient is φ = 196969818.

The previous prime is 393939587. The next prime is 393939677. The reversal of 393939638 is 836939393.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 836939393 = 17 ⋅49231729.

It is a self number, because there is not a number n which added to its sum of digits gives 393939638.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 98484908 + ... + 98484911.

It is an arithmetic number, because the mean of its divisors is an integer number (147727365).

Almost surely, 2^393939638 is an apocalyptic number.

393939638 is a deficient number, since it is larger than the sum of its proper divisors (196969822).

393939638 is a wasteful number, since it uses less digits than its factorization.

393939638 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 196969821.

The product of its digits is 2834352, while the sum is 53.

The square root of 393939638 is about 19847.9126862247. The cubic root of 393939638 is about 733.0662532003.

The spelling of 393939638 in words is "three hundred ninety-three million, nine hundred thirty-nine thousand, six hundred thirty-eight".