61128561 has 16 divisors (see below), whose sum is σ = 88046784. Its totient is φ = 37500864.

The previous prime is 61128547. The next prime is 61128563. The reversal of 61128561 is 16582116.

It is not a de Polignac number, because 61128561 - 2⁹ = 61128049 is a prime.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (61128563) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 11275 + ... + 15791.

It is an arithmetic number, because the mean of its divisors is an integer number (5502924).

Almost surely, 2^61128561 is an apocalyptic number.

It is an amenable number.

61128561 is a deficient number, since it is larger than the sum of its proper divisors (26918223).

61128561 is a wasteful number, since it uses less digits than its factorization.

61128561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4880.

The product of its digits is 2880, while the sum is 30.

The square root of 61128561 is about 7818.4756186868. The cubic root of 61128561 is about 393.9260707141.

The spelling of 61128561 in words is "sixty-one million, one hundred twenty-eight thousand, five hundred sixty-one".