640310207 has 4 divisors (see below), whose sum is σ = 642396216. Its totient is φ = 638224200.

The previous prime is 640310201. The next prime is 640310261. The reversal of 640310207 is 702013046.

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 640310207 - 2²² = 636115903 is a prime.

It is a super-2 number, since 2×640310207² = 819994322376765698, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640310201) 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, 1042544 + ... + 1043157.

It is an arithmetic number, because the mean of its divisors is an integer number (160599054).

Almost surely, 2^640310207 is an apocalyptic number.

640310207 is a deficient number, since it is larger than the sum of its proper divisors (2086009).

640310207 is a wasteful number, since it uses less digits than its factorization.

640310207 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2086008.

The product of its (nonzero) digits is 1008, while the sum is 23.

The square root of 640310207 is about 25304.3515427683. The cubic root of 640310207 is about 861.9130870071.

The spelling of 640310207 in words is "six hundred forty million, three hundred ten thousand, two hundred seven".