640212654663 has 24 divisors (see below), whose sum is σ = 973658220080. Its totient is φ = 404247024000.

The previous prime is 640212654619. The next prime is 640212654671. The reversal of 640212654663 is 366456212046.

It is a happy number.

640212654663 is a `hidden beast` number, since 6 + 4 + 0 + 21 + 26 + 546 + 63 = 666.

It is not a de Polignac number, because 640212654663 - 2¹⁶ = 640212589127 is a prime.

It is a Smith number, since the sum of its digits (45) coincides with the sum of the digits of its prime factors.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640212650663) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 259413 + ... + 1160913.

Almost surely, 2^640212654663 is an apocalyptic number.

640212654663 is a deficient number, since it is larger than the sum of its proper divisors (333445565417).

640212654663 is a wasteful number, since it uses less digits than its factorization.

640212654663 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 905679 (or 905676 counting only the distinct ones).

The product of its (nonzero) digits is 1244160, while the sum is 45.

The spelling of 640212654663 in words is "six hundred forty billion, two hundred twelve million, six hundred fifty-four thousand, six hundred sixty-three".