640756601 has 4 divisors (see below), whose sum is σ = 641624400. Its totient is φ = 639888804.

The previous prime is 640756583. The next prime is 640756607. The reversal of 640756601 is 106657046.

640756601 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-640756601 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (640756607) 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, 432791 + ... + 434268.

It is an arithmetic number, because the mean of its divisors is an integer number (160406100).

Almost surely, 2^640756601 is an apocalyptic number.

It is an amenable number.

640756601 is a deficient number, since it is larger than the sum of its proper divisors (867799).

640756601 is an equidigital number, since it uses as much as digits as its factorization.

640756601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 867798.

The product of its (nonzero) digits is 30240, while the sum is 35.

The square root of 640756601 is about 25313.1705046997. The cubic root of 640756601 is about 862.1133354963.

The spelling of 640756601 in words is "six hundred forty million, seven hundred fifty-six thousand, six hundred one".