399739247 has 2 divisors, whose sum is σ = 399739248. Its totient is φ = 399739246.

The previous prime is 399739213. The next prime is 399739261. The reversal of 399739247 is 742937993.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 399739247 - 2¹² = 399735151 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (399735247) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199869623 + 199869624.

It is an arithmetic number, because the mean of its divisors is an integer number (199869624).

Almost surely, 2^399739247 is an apocalyptic number.

399739247 is a deficient number, since it is larger than the sum of its proper divisors (1).

399739247 is an equidigital number, since it uses as much as digits as its factorization.

399739247 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2571912, while the sum is 53.

The square root of 399739247 is about 19993.4801122766. The cubic root of 399739247 is about 736.6461612150.

The spelling of 399739247 in words is "three hundred ninety-nine million, seven hundred thirty-nine thousand, two hundred forty-seven".