640311227 has 4 divisors (see below), whose sum is σ = 655928616. Its totient is φ = 624693840.

The previous prime is 640311197. The next prime is 640311313. The reversal of 640311227 is 722113046.

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 640311227 - 2⁸ = 640310971 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 640311196 and 640311205.

It is not an unprimeable number, because it can be changed into a prime (640311527) 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, 7808633 + ... + 7808714.

It is an arithmetic number, because the mean of its divisors is an integer number (163982154).

Almost surely, 2^640311227 is an apocalyptic number.

640311227 is a deficient number, since it is larger than the sum of its proper divisors (15617389).

640311227 is a wasteful number, since it uses less digits than its factorization.

640311227 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15617388.

The product of its (nonzero) digits is 2016, while the sum is 26.

The square root of 640311227 is about 25304.3716973965. The cubic root of 640311227 is about 861.9135446764.

The spelling of 640311227 in words is "six hundred forty million, three hundred eleven thousand, two hundred twenty-seven".