400640459 has 4 divisors (see below), whose sum is σ = 400739640. Its totient is φ = 400541280.

The previous prime is 400640453. The next prime is 400640467. The reversal of 400640459 is 954046004.

It is a happy number.

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 400640459 - 2⁸ = 400640203 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (400640453) 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, 43262 + ... + 51699.

It is an arithmetic number, because the mean of its divisors is an integer number (100184910).

Almost surely, 2^400640459 is an apocalyptic number.

400640459 is a deficient number, since it is larger than the sum of its proper divisors (99181).

400640459 is an equidigital number, since it uses as much as digits as its factorization.

400640459 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 99180.

The product of its (nonzero) digits is 17280, while the sum is 32.

The square root of 400640459 is about 20016.0050709426. The cubic root of 400640459 is about 737.1993352217.

The spelling of 400640459 in words is "four hundred million, six hundred forty thousand, four hundred fifty-nine".