640261243546264 has 8 divisors (see below), whose sum is σ = 1200489831649260. Its totient is φ = 320130621773128.

The previous prime is 640261243546247. The next prime is 640261243546289. The reversal of 640261243546264 is 462645342162046.

It is a tau number, because it is divible by the number of its divisors (8).

It is a hoax number, since the sum of its digits (55) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 40016327721634 + ... + 40016327721649.

Almost surely, 2^{640261243546264} is an apocalyptic number.

It is an amenable number.

640261243546264 is a deficient number, since it is larger than the sum of its proper divisors (560228588102996).

640261243546264 is a wasteful number, since it uses less digits than its factorization.

640261243546264 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 80032655443289 (or 80032655443285 counting only the distinct ones).

The product of its (nonzero) digits is 39813120, while the sum is 55.

The spelling of 640261243546264 in words is "six hundred forty trillion, two hundred sixty-one billion, two hundred forty-three million, five hundred forty-six thousand, two hundred sixty-four".