394342639 has 2 divisors, whose sum is σ = 394342640. Its totient is φ = 394342638.

The previous prime is 394342621. The next prime is 394342649. The reversal of 394342639 is 936243493.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 394342639 - 2¹¹ = 394340591 is a prime.

It is a super-2 number, since 2×394342639² = 311012233866968642, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 394342595 and 394342604.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (394342649) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 197171319 + 197171320.

It is an arithmetic number, because the mean of its divisors is an integer number (197171320).

Almost surely, 2^394342639 is an apocalyptic number.

394342639 is a deficient number, since it is larger than the sum of its proper divisors (1).

394342639 is an equidigital number, since it uses as much as digits as its factorization.

394342639 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 419904, while the sum is 43.

The square root of 394342639 is about 19858.0623173561. The cubic root of 394342639 is about 733.3161440645.

The spelling of 394342639 in words is "three hundred ninety-four million, three hundred forty-two thousand, six hundred thirty-nine".