61011055561 has 2 divisors, whose sum is σ = 61011055562. Its totient is φ = 61011055560.

The previous prime is 61011055543. The next prime is 61011055663. The reversal of 61011055561 is 16555011016.

61011055561 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., 51810409161 + 9200646400 = 227619^2 + 95920^2 .

It is a cyclic number.

It is not a de Polignac number, because 61011055561 - 2¹⁹ = 61010531273 is a prime.

It is not a weakly prime, because it can be changed into another prime (61011055541) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30505527780 + 30505527781.

It is an arithmetic number, because the mean of its divisors is an integer number (30505527781).

Almost surely, 2^61011055561 is an apocalyptic number.

It is an amenable number.

61011055561 is a deficient number, since it is larger than the sum of its proper divisors (1).

61011055561 is an equidigital number, since it uses as much as digits as its factorization.

61011055561 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4500, while the sum is 31.

Adding to 61011055561 its reverse (16555011016), we get a palindrome (77566066577).

The spelling of 61011055561 in words is "sixty-one billion, eleven million, fifty-five thousand, five hundred sixty-one".