640446971355 has 12 divisors (see below), whose sum is σ = 1110108083760. Its totient is φ = 341571718032.

The previous prime is 640446971341. The next prime is 640446971363. The reversal of 640446971355 is 553179644046.

It is a happy number.

640446971355 is a `hidden beast` number, since 6 + 40 + 4 + 469 + 7 + 135 + 5 = 666.

It is not a de Polignac number, because 640446971355 - 2⁵ = 640446971323 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7116077415 + ... + 7116077504.

It is an arithmetic number, because the mean of its divisors is an integer number (92509006980).

Almost surely, 2^640446971355 is an apocalyptic number.

640446971355 is a deficient number, since it is larger than the sum of its proper divisors (469661112405).

640446971355 is a wasteful number, since it uses less digits than its factorization.

640446971355 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14232154930 (or 14232154927 counting only the distinct ones).

The product of its (nonzero) digits is 10886400, while the sum is 54.

The spelling of 640446971355 in words is "six hundred forty billion, four hundred forty-six million, nine hundred seventy-one thousand, three hundred fifty-five".