561878878181 has 2 divisors, whose sum is σ = 561878878182. Its totient is φ = 561878878180.

The previous prime is 561878878159. The next prime is 561878878219. The reversal of 561878878181 is 181878878165.

561878878181 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 418135529956 + 143743348225 = 646634^2 + 379135^2 .

It is a cyclic number.

It is not a de Polignac number, because 561878878181 - 2³⁰ = 560805136357 is a prime.

It is a super-2 number, since 2×561878878181² (a number of 24 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (561878878081) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 280939439090 + 280939439091.

It is an arithmetic number, because the mean of its divisors is an integer number (280939439091).

Almost surely, 2^561878878181 is an apocalyptic number.

It is an amenable number.

561878878181 is a deficient number, since it is larger than the sum of its proper divisors (1).

561878878181 is an equidigital number, since it uses as much as digits as its factorization.

561878878181 is an evil number, because the sum of its binary digits is even.

The product of its digits is 48168960, while the sum is 68.

The spelling of 561878878181 in words is "five hundred sixty-one billion, eight hundred seventy-eight million, eight hundred seventy-eight thousand, one hundred eighty-one".