6115561 has 2 divisors, whose sum is σ = 6115562. Its totient is φ = 6115560.

The previous prime is 6115547. The next prime is 6115579. The reversal of 6115561 is 1655116.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6095961 + 19600 = 2469^2 + 140^2 .

It is a cyclic number.

It is not a de Polignac number, because 6115561 - 2¹⁹ = 5591273 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (6115531) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3057780 + 3057781.

It is an arithmetic number, because the mean of its divisors is an integer number (3057781).

Almost surely, 2^6115561 is an apocalyptic number.

It is an amenable number.

6115561 is a deficient number, since it is larger than the sum of its proper divisors (1).

6115561 is an equidigital number, since it uses as much as digits as its factorization.

6115561 is an evil number, because the sum of its binary digits is even.

The product of its digits is 900, while the sum is 25.

The square root of 6115561 is about 2472.9660329248. The cubic root of 6115561 is about 182.8712502776.

It can be divided in two parts, 61155 and 61, that added together give a palindrome (61216).

The spelling of 6115561 in words is "six million, one hundred fifteen thousand, five hundred sixty-one".