640451323687 has 16 divisors (see below), whose sum is σ = 757412490240. Its totient is φ = 529868620512.

The previous prime is 640451323669. The next prime is 640451323691. The reversal of 640451323687 is 786323154046.

It is not a de Polignac number, because 640451323687 - 2¹¹ = 640451321639 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 640451323687.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640451323487) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 199858 + ... + 1149280.

It is an arithmetic number, because the mean of its divisors is an integer number (47338280640).

Almost surely, 2^640451323687 is an apocalyptic number.

640451323687 is a deficient number, since it is larger than the sum of its proper divisors (116961166553).

640451323687 is a wasteful number, since it uses less digits than its factorization.

640451323687 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 952782.

The product of its (nonzero) digits is 2903040, while the sum is 49.

The spelling of 640451323687 in words is "six hundred forty billion, four hundred fifty-one million, three hundred twenty-three thousand, six hundred eighty-seven".