61611561 has 48 divisors (see below), whose sum is σ = 102053952. Its totient is φ = 35481600.

The previous prime is 61611551. The next prime is 61611569. The reversal of 61611561 is 16511616.

61611561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 61611561 - 2⁶ = 61611497 is a prime.

It is not an unprimeable number, because it can be changed into a prime (61611569) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 174361 + ... + 174713.

It is an arithmetic number, because the mean of its divisors is an integer number (2126124).

Almost surely, 2^61611561 is an apocalyptic number.

It is an amenable number.

61611561 is a deficient number, since it is larger than the sum of its proper divisors (40442391).

61611561 is a wasteful number, since it uses less digits than its factorization.

61611561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 454 (or 451 counting only the distinct ones).

The product of its digits is 1080, while the sum is 27.

The square root of 61611561 is about 7849.3032174837. The cubic root of 61611561 is about 394.9608699154.

The spelling of 61611561 in words is "sixty-one million, six hundred eleven thousand, five hundred sixty-one".