400647217 has 4 divisors (see below), whose sum is σ = 400694896. Its totient is φ = 400599540.

The previous prime is 400647197. The next prime is 400647227. The reversal of 400647217 is 712746004.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 400647217 - 2⁷ = 400647089 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (400647227) 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, 7503 + ... + 29284.

It is an arithmetic number, because the mean of its divisors is an integer number (100173724).

Almost surely, 2^400647217 is an apocalyptic number.

It is an amenable number.

400647217 is a deficient number, since it is larger than the sum of its proper divisors (47679).

400647217 is a wasteful number, since it uses less digits than its factorization.

400647217 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47678.

The product of its (nonzero) digits is 9408, while the sum is 31.

The square root of 400647217 is about 20016.1738851360. The cubic root of 400647217 is about 737.2034802225.

The spelling of 400647217 in words is "four hundred million, six hundred forty-seven thousand, two hundred seventeen".