56643546521 has 4 divisors (see below), whose sum is σ = 56931077412. Its totient is φ = 56356015632.

The previous prime is 56643546517. The next prime is 56643546563. The reversal of 56643546521 is 12564534665.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 55288938496 + 1354608025 = 235136^2 + 36805^2 .

It is a cyclic number.

It is not a de Polignac number, because 56643546521 - 2² = 56643546517 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (56643546511) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 143765150 + ... + 143765543.

It is an arithmetic number, because the mean of its divisors is an integer number (14232769353).

Almost surely, 2^56643546521 is an apocalyptic number.

It is an amenable number.

56643546521 is a deficient number, since it is larger than the sum of its proper divisors (287530891).

56643546521 is a wasteful number, since it uses less digits than its factorization.

56643546521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 287530890.

The product of its digits is 2592000, while the sum is 47.

The spelling of 56643546521 in words is "fifty-six billion, six hundred forty-three million, five hundred forty-six thousand, five hundred twenty-one".