640642266625 has 32 divisors (see below), whose sum is σ = 814939826688. Its totient is φ = 502696022400.

The previous prime is 640642266623. The next prime is 640642266659. The reversal of 640642266625 is 526662246046.

It is not a de Polignac number, because 640642266625 - 2¹ = 640642266623 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (640642266623) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 1787224 + ... + 2115526.

It is an arithmetic number, because the mean of its divisors is an integer number (25466869584).

Almost surely, 2^640642266625 is an apocalyptic number.

It is an amenable number.

640642266625 is a deficient number, since it is larger than the sum of its proper divisors (174297560063).

640642266625 is a wasteful number, since it uses less digits than its factorization.

640642266625 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 328618 (or 328608 counting only the distinct ones).

The product of its (nonzero) digits is 4976640, while the sum is 49.

The spelling of 640642266625 in words is "six hundred forty billion, six hundred forty-two million, two hundred sixty-six thousand, six hundred twenty-five".