640924663 has 8 divisors (see below), whose sum is σ = 674963120. Its totient is φ = 606916800.

The previous prime is 640924651. The next prime is 640924703. The reversal of 640924663 is 366429046.

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 640924663 - 2²⁹ = 104053751 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640928663) 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, 44563 + ... + 57163.

It is an arithmetic number, because the mean of its divisors is an integer number (84370390).

Almost surely, 2^640924663 is an apocalyptic number.

640924663 is a deficient number, since it is larger than the sum of its proper divisors (34038457).

640924663 is a wasteful number, since it uses less digits than its factorization.

640924663 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15297.

The product of its (nonzero) digits is 186624, while the sum is 40.

The square root of 640924663 is about 25316.4899423281. The cubic root of 640924663 is about 862.1887025575.

The spelling of 640924663 in words is "six hundred forty million, nine hundred twenty-four thousand, six hundred sixty-three".