399774439 has 2 divisors, whose sum is σ = 399774440. Its totient is φ = 399774438.

The previous prime is 399774413. The next prime is 399774457. The reversal of 399774439 is 934477993.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 399774439 - 2¹⁷ = 399643367 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 399774439.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (399774409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199887219 + 199887220.

It is an arithmetic number, because the mean of its divisors is an integer number (199887220).

Almost surely, 2^399774439 is an apocalyptic number.

399774439 is a deficient number, since it is larger than the sum of its proper divisors (1).

399774439 is an equidigital number, since it uses as much as digits as its factorization.

399774439 is an evil number, because the sum of its binary digits is even.

The product of its digits is 5143824, while the sum is 55.

The square root of 399774439 is about 19994.3601798107. The cubic root of 399774439 is about 736.6677780491.

The spelling of 399774439 in words is "three hundred ninety-nine million, seven hundred seventy-four thousand, four hundred thirty-nine".