400019999 has 2 divisors, whose sum is σ = 400020000. Its totient is φ = 400019998.

The previous prime is 400019993. The next prime is 400020007. The reversal of 400019999 is 999910004.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 400019999 - 2⁸ = 400019743 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (400019993) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200009999 + 200010000.

It is an arithmetic number, because the mean of its divisors is an integer number (200010000).

Almost surely, 2^400019999 is an apocalyptic number.

400019999 is a deficient number, since it is larger than the sum of its proper divisors (1).

400019999 is an equidigital number, since it uses as much as digits as its factorization.

400019999 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 26244, while the sum is 41.

The square root of 400019999 is about 20000.4999687508. The cubic root of 400019999 is about 736.8185790144.

The spelling of 400019999 in words is "four hundred million, nineteen thousand, nine hundred ninety-nine".