402400399 has 2 divisors, whose sum is σ = 402400400. Its totient is φ = 402400398.

The previous prime is 402400337. The next prime is 402400441. The reversal of 402400399 is 993004204.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 402400399 - 2⁹ = 402399887 is a prime.

It is a super-2 number, since 2×402400399² = 323852162230718402, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 402400399.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (402400499) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 201200199 + 201200200.

It is an arithmetic number, because the mean of its divisors is an integer number (201200200).

Almost surely, 2^402400399 is an apocalyptic number.

402400399 is a deficient number, since it is larger than the sum of its proper divisors (1).

402400399 is an equidigital number, since it uses as much as digits as its factorization.

402400399 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7776, while the sum is 31.

The square root of 402400399 is about 20059.9202141983. The cubic root of 402400399 is about 738.2772189002.

The spelling of 402400399 in words is "four hundred two million, four hundred thousand, three hundred ninety-nine".