406399999 has 4 divisors (see below), whose sum is σ = 409323880. Its totient is φ = 403476120.

The previous prime is 406399991. The next prime is 406400003. The reversal of 406399999 is 999993604.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 406399999 - 2³ = 406399991 is a prime.

It is a Duffinian number.

406399999 is a modest number, since divided by 99999 gives 4063 as remainder.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (406399991) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1461732 + ... + 1462009.

It is an arithmetic number, because the mean of its divisors is an integer number (102330970).

Almost surely, 2^406399999 is an apocalyptic number.

406399999 is a deficient number, since it is larger than the sum of its proper divisors (2923881).

406399999 is a wasteful number, since it uses less digits than its factorization.

406399999 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2923880.

The product of its (nonzero) digits is 4251528, while the sum is 58.

The square root of 406399999 is about 20159.3650445643. The cubic root of 406399999 is about 740.7151590029.

The spelling of 406399999 in words is "four hundred six million, three hundred ninety-nine thousand, nine hundred ninety-nine".