399951407 has 2 divisors, whose sum is σ = 399951408. Its totient is φ = 399951406.

The previous prime is 399951403. The next prime is 399951427. The reversal of 399951407 is 704159993.

It is a weak prime.

It is an emirp because it is prime and its reverse (704159993) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 399951407 - 2² = 399951403 is a prime.

It is a super-2 number, since 2×399951407² = 319922255922559298, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (399951403) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199975703 + 199975704.

It is an arithmetic number, because the mean of its divisors is an integer number (199975704).

Almost surely, 2^399951407 is an apocalyptic number.

399951407 is a deficient number, since it is larger than the sum of its proper divisors (1).

399951407 is an equidigital number, since it uses as much as digits as its factorization.

399951407 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 306180, while the sum is 47.

The square root of 399951407 is about 19998.7851381028. The cubic root of 399951407 is about 736.7764621627.

The spelling of 399951407 in words is "three hundred ninety-nine million, nine hundred fifty-one thousand, four hundred seven".