399354409 has 2 divisors, whose sum is σ = 399354410. Its totient is φ = 399354408.

The previous prime is 399354383. The next prime is 399354427. The reversal of 399354409 is 904453993.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 230432400 + 168922009 = 15180^2 + 12997^2 .

It is an emirp because it is prime and its reverse (904453993) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 399354409 - 2¹⁵ = 399321641 is a prime.

It is not a weakly prime, because it can be changed into another prime (399352409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 199677204 + 199677205.

It is an arithmetic number, because the mean of its divisors is an integer number (199677205).

Almost surely, 2^399354409 is an apocalyptic number.

It is an amenable number.

399354409 is a deficient number, since it is larger than the sum of its proper divisors (1).

399354409 is an equidigital number, since it uses as much as digits as its factorization.

399354409 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 524880, while the sum is 46.

The square root of 399354409 is about 19983.8537074309. The cubic root of 399354409 is about 736.4096900152.

It can be divided in two parts, 39935 and 4409, that added together give a palindrome (44344).

The spelling of 399354409 in words is "three hundred ninety-nine million, three hundred fifty-four thousand, four hundred nine".