393838649 has 4 divisors (see below), whose sum is σ = 393895680. Its totient is φ = 393781620.

The previous prime is 393838639. The next prime is 393838651. The reversal of 393838649 is 946838393.

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 a de Polignac number, because none of the positive numbers 2^k-393838649 is a prime.

It is a super-2 number, since 2×393838649² = 310217762892290402, which contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 393838649.

It is not an unprimeable number, because it can be changed into a prime (393838639) 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, 16457 + ... + 32534.

It is an arithmetic number, because the mean of its divisors is an integer number (98473920).

Almost surely, 2^393838649 is an apocalyptic number.

It is an amenable number.

393838649 is a deficient number, since it is larger than the sum of its proper divisors (57031).

393838649 is an equidigital number, since it uses as much as digits as its factorization.

393838649 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57030.

The product of its digits is 3359232, while the sum is 53.

The square root of 393838649 is about 19845.3684521099. The cubic root of 393838649 is about 733.0036057388.

The spelling of 393838649 in words is "three hundred ninety-three million, eight hundred thirty-eight thousand, six hundred forty-nine".