656555043654021 has 8 divisors (see below), whose sum is σ = 877496001066720. Its totient is φ = 436658724338672.

The previous prime is 656555043653953. The next prime is 656555043654031. The reversal of 656555043654021 is 120456340555656.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 656555043654021 - 2¹³ = 656555043645829 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (656555043654031) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 261159522870 + ... + 261159525383.

It is an arithmetic number, because the mean of its divisors is an integer number (109687000133340).

Almost surely, 2^{656555043654021} is an apocalyptic number.

It is an amenable number.

656555043654021 is a deficient number, since it is larger than the sum of its proper divisors (220940957412699).

656555043654021 is a wasteful number, since it uses less digits than its factorization.

656555043654021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 522319048675.

The product of its (nonzero) digits is 64800000, while the sum is 57.

The spelling of 656555043654021 in words is "six hundred fifty-six trillion, five hundred fifty-five billion, forty-three million, six hundred fifty-four thousand, twenty-one".