56171853581 has 2 divisors, whose sum is σ = 56171853582. Its totient is φ = 56171853580.

The previous prime is 56171853553. The next prime is 56171853607. The reversal of 56171853581 is 18535817165.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 55239100900 + 932752681 = 235030^2 + 30541^2 .

It is a cyclic number.

It is not a de Polignac number, because 56171853581 - 2²² = 56167659277 is a prime.

It is a super-2 number, since 2×56171853581² (a number of 22 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (56171853541) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28085926790 + 28085926791.

It is an arithmetic number, because the mean of its divisors is an integer number (28085926791).

Almost surely, 2^56171853581 is an apocalyptic number.

It is an amenable number.

56171853581 is a deficient number, since it is larger than the sum of its proper divisors (1).

56171853581 is an equidigital number, since it uses as much as digits as its factorization.

56171853581 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 1008000, while the sum is 50.

The spelling of 56171853581 in words is "fifty-six billion, one hundred seventy-one million, eight hundred fifty-three thousand, five hundred eighty-one".