640656653 has 8 divisors (see below), whose sum is σ = 788500608. Its totient is φ = 506893104.

The previous prime is 640656647. The next prime is 640656659. The reversal of 640656653 is 356656046.

It is a happy number.

640656653 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (640656647) and next prime (640656659).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 640656653 - 2⁴ = 640656637 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 640656653.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640656659) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3520001 + ... + 3520182.

It is an arithmetic number, because the mean of its divisors is an integer number (98562576).

Almost surely, 2^640656653 is an apocalyptic number.

It is an amenable number.

640656653 is a deficient number, since it is larger than the sum of its proper divisors (147843955).

640656653 is a wasteful number, since it uses less digits than its factorization.

640656653 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7040203.

The product of its (nonzero) digits is 388800, while the sum is 41.

The square root of 640656653 is about 25311.1961985205. The cubic root of 640656653 is about 862.0685077702.

The spelling of 640656653 in words is "six hundred forty million, six hundred fifty-six thousand, six hundred fifty-three".