640656600055 has 16 divisors (see below), whose sum is σ = 802254435840. Its totient is φ = 490216544928.

The previous prime is 640656600041. The next prime is 640656600061. The reversal of 640656600055 is 550006656046.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-640656600055 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 640656599984 and 640656600020.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2302126 + ... + 2565364.

It is an arithmetic number, because the mean of its divisors is an integer number (50140902240).

Almost surely, 2^640656600055 is an apocalyptic number.

640656600055 is a deficient number, since it is larger than the sum of its proper divisors (161597835785).

640656600055 is a wasteful number, since it uses less digits than its factorization.

640656600055 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 284430.

The product of its (nonzero) digits is 648000, while the sum is 43.

The spelling of 640656600055 in words is "six hundred forty billion, six hundred fifty-six million, six hundred thousand, fifty-five".