400239899 has 2 divisors, whose sum is σ = 400239900. Its totient is φ = 400239898.

The previous prime is 400239881. The next prime is 400239901. The reversal of 400239899 is 998932004.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 400239899 - 2¹⁶ = 400174363 is a prime.

Together with 400239901, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (400239809) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200119949 + 200119950.

It is an arithmetic number, because the mean of its divisors is an integer number (200119950).

Almost surely, 2^400239899 is an apocalyptic number.

400239899 is a deficient number, since it is larger than the sum of its proper divisors (1).

400239899 is an equidigital number, since it uses as much as digits as its factorization.

400239899 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 139968, while the sum is 44.

The square root of 400239899 is about 20005.9965760269. The cubic root of 400239899 is about 736.9535695358.

The spelling of 400239899 in words is "four hundred million, two hundred thirty-nine thousand, eight hundred ninety-nine".