640714215861 has 8 divisors (see below), whose sum is σ = 949206245760. Its totient is φ = 427142810556.

The previous prime is 640714215811. The next prime is 640714215863. The reversal of 640714215861 is 168512417046.

640714215861 is a `hidden beast` number, since 6 + 40 + 7 + 1 + 4 + 21 + 586 + 1 = 666.

It is not a de Polignac number, because 640714215861 - 2⁶ = 640714215797 is a prime.

It is a super-2 number, since 2×640714215861² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (640714215863) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11865078045 + ... + 11865078098.

It is an arithmetic number, because the mean of its divisors is an integer number (118650780720).

Almost surely, 2^640714215861 is an apocalyptic number.

It is an amenable number.

640714215861 is a deficient number, since it is larger than the sum of its proper divisors (308492029899).

640714215861 is a wasteful number, since it uses less digits than its factorization.

640714215861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23730156152 (or 23730156146 counting only the distinct ones).

The product of its (nonzero) digits is 322560, while the sum is 45.

The spelling of 640714215861 in words is "six hundred forty billion, seven hundred fourteen million, two hundred fifteen thousand, eight hundred sixty-one".