640907595 has 24 divisors (see below), whose sum is σ = 1127492496. Its totient is φ = 336714048.

The previous prime is 640907591. The next prime is 640907621. The reversal of 640907595 is 595709046.

It is a happy number.

It is not a de Polignac number, because 640907595 - 2² = 640907591 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 640907595.

It is not an unprimeable number, because it can be changed into a prime (640907591) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 103272 + ... + 109301.

It is an arithmetic number, because the mean of its divisors is an integer number (46978854).

Almost surely, 2^640907595 is an apocalyptic number.

640907595 is a deficient number, since it is larger than the sum of its proper divisors (486584901).

640907595 is a wasteful number, since it uses less digits than its factorization.

640907595 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 212651 (or 212648 counting only the distinct ones).

The product of its (nonzero) digits is 340200, while the sum is 45.

The square root of 640907595 is about 25316.1528475398. The cubic root of 640907595 is about 862.1810490488.

The spelling of 640907595 in words is "six hundred forty million, nine hundred seven thousand, five hundred ninety-five".