56781694517 has 2 divisors, whose sum is σ = 56781694518. Its totient is φ = 56781694516.

The previous prime is 56781694507. The next prime is 56781694523. The reversal of 56781694517 is 71549618765.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 54812642641 + 1969051876 = 234121^2 + 44374^2 .

It is a cyclic number.

It is not a de Polignac number, because 56781694517 - 2¹² = 56781690421 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (56781694507) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 28390847258 + 28390847259.

It is an arithmetic number, because the mean of its divisors is an integer number (28390847259).

Almost surely, 2^56781694517 is an apocalyptic number.

It is an amenable number.

56781694517 is a deficient number, since it is larger than the sum of its proper divisors (1).

56781694517 is an equidigital number, since it uses as much as digits as its factorization.

56781694517 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12700800, while the sum is 59.

The spelling of 56781694517 in words is "fifty-six billion, seven hundred eighty-one million, six hundred ninety-four thousand, five hundred seventeen".