400128899 has 2 divisors, whose sum is σ = 400128900. Its totient is φ = 400128898.

The previous prime is 400128877. The next prime is 400128929. The reversal of 400128899 is 998821004.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 400128899 - 2²⁰ = 399080323 is a prime.

It is not a weakly prime, because it can be changed into another prime (400128299) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 200064449 + 200064450.

It is an arithmetic number, because the mean of its divisors is an integer number (200064450).

Almost surely, 2^400128899 is an apocalyptic number.

400128899 is a deficient number, since it is larger than the sum of its proper divisors (1).

400128899 is an equidigital number, since it uses as much as digits as its factorization.

400128899 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 41472, while the sum is 41.

The square root of 400128899 is about 20003.2222154332. Note that the first 4 decimals coincide. The cubic root of 400128899 is about 736.8854358909.

The spelling of 400128899 in words is "four hundred million, one hundred twenty-eight thousand, eight hundred ninety-nine".