61115111081 has 2 divisors, whose sum is σ = 61115111082. Its totient is φ = 61115111080.

The previous prime is 61115111077. The next prime is 61115111093. The reversal of 61115111081 is 18011151116.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 46681491481 + 14433619600 = 216059^2 + 120140^2 .

It is a cyclic number.

It is not a de Polignac number, because 61115111081 - 2² = 61115111077 is a prime.

It is a super-3 number, since 3×61115111081³ (a number of 33 digits) contains 333 as substring. Note that it is a super-d number also for d = 2.

It is a self number, because there is not a number n which added to its sum of digits gives 61115111081.

It is not a weakly prime, because it can be changed into another prime (61115111051) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30557555540 + 30557555541.

It is an arithmetic number, because the mean of its divisors is an integer number (30557555541).

Almost surely, 2^61115111081 is an apocalyptic number.

It is an amenable number.

61115111081 is a deficient number, since it is larger than the sum of its proper divisors (1).

61115111081 is an equidigital number, since it uses as much as digits as its factorization.

61115111081 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 240, while the sum is 26.

Adding to 61115111081 its reverse (18011151116), we get a palindrome (79126262197).

The spelling of 61115111081 in words is "sixty-one billion, one hundred fifteen million, one hundred eleven thousand, eighty-one".