394978308239 has 4 divisors (see below), whose sum is σ = 394981794480. Its totient is φ = 394974822000.

The previous prime is 394978308211. The next prime is 394978308251. The reversal of 394978308239 is 932803879493.

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

It is a cyclic number.

It is not a de Polignac number, because 394978308239 - 2²⁴ = 394961531023 is a prime.

It is a super-2 number, since 2×394978308239² (a number of 24 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (394978308269) 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, 1567262 + ... + 1801739.

It is an arithmetic number, because the mean of its divisors is an integer number (98745448620).

Almost surely, 2^394978308239 is an apocalyptic number.

394978308239 is a deficient number, since it is larger than the sum of its proper divisors (3486241).

394978308239 is a wasteful number, since it uses less digits than its factorization.

394978308239 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3486240.

The product of its (nonzero) digits is 70543872, while the sum is 65.

The spelling of 394978308239 in words is "three hundred ninety-four billion, nine hundred seventy-eight million, three hundred eight thousand, two hundred thirty-nine".