640465027 has 4 divisors (see below), whose sum is σ = 644763600. Its totient is φ = 636166456.

The previous prime is 640465019. The next prime is 640465031. The reversal of 640465027 is 720564046.

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 640465027 - 2³ = 640465019 is a prime.

It is a super-2 number, since 2×640465027² = 820390901620221458, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 640464983 and 640465001.

It is not an unprimeable number, because it can be changed into a prime (640465037) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2149063 + ... + 2149360.

It is an arithmetic number, because the mean of its divisors is an integer number (161190900).

Almost surely, 2^640465027 is an apocalyptic number.

640465027 is a deficient number, since it is larger than the sum of its proper divisors (4298573).

640465027 is a wasteful number, since it uses less digits than its factorization.

640465027 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4298572.

The product of its (nonzero) digits is 40320, while the sum is 34.

The square root of 640465027 is about 25307.4105154992. The cubic root of 640465027 is about 861.9825484594.

The spelling of 640465027 in words is "six hundred forty million, four hundred sixty-five thousand, twenty-seven".