56178781681 has 8 divisors (see below), whose sum is σ = 61293412224. Its totient is φ = 51065395920.

The previous prime is 56178781579. The next prime is 56178781697. The reversal of 56178781681 is 18618787165.

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

It is not a de Polignac number, because 56178781681 - 2¹³ = 56178773489 is a prime.

It is a super-2 number, since 2×56178781681² (a number of 22 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (56178181681) 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, 215545 + ... + 398518.

It is an arithmetic number, because the mean of its divisors is an integer number (7661676528).

Almost surely, 2^56178781681 is an apocalyptic number.

It is an amenable number.

56178781681 is a deficient number, since it is larger than the sum of its proper divisors (5114630543).

56178781681 is a wasteful number, since it uses less digits than its factorization.

56178781681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 622391.

The product of its digits is 4515840, while the sum is 58.

The spelling of 56178781681 in words is "fifty-six billion, one hundred seventy-eight million, seven hundred eighty-one thousand, six hundred eighty-one".