56821863517 has 4 divisors (see below), whose sum is σ = 58357589596. Its totient is φ = 55286137440.

The previous prime is 56821863491. The next prime is 56821863521. The reversal of 56821863517 is 71536812865.

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 51687567801 + 5134295716 = 227349^2 + 71654^2 .

It is a cyclic number.

It is not a de Polignac number, because 56821863517 - 2¹¹ = 56821861469 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (56821863017) 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, 767862984 + ... + 767863057.

It is an arithmetic number, because the mean of its divisors is an integer number (14589397399).

Almost surely, 2^56821863517 is an apocalyptic number.

It is an amenable number.

56821863517 is a deficient number, since it is larger than the sum of its proper divisors (1535726079).

56821863517 is a wasteful number, since it uses less digits than its factorization.

56821863517 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1535726078.

The product of its digits is 2419200, while the sum is 52.

The spelling of 56821863517 in words is "fifty-six billion, eight hundred twenty-one million, eight hundred sixty-three thousand, five hundred seventeen".