61561518 has 16 divisors (see below), whose sum is σ = 123202560. Its totient is φ = 20507256.

The previous prime is 61561483. The next prime is 61561529. The reversal of 61561518 is 81516516.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 12723 + ... + 16881.

It is an arithmetic number, because the mean of its divisors is an integer number (7700160).

Almost surely, 2^61561518 is an apocalyptic number.

61561518 is an abundant number, since it is smaller than the sum of its proper divisors (61641042).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

61561518 is a wasteful number, since it uses less digits than its factorization.

61561518 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6631.

The product of its digits is 7200, while the sum is 33.

The square root of 61561518 is about 7846.1148347446. The cubic root of 61561518 is about 394.8539074114.

The spelling of 61561518 in words is "sixty-one million, five hundred sixty-one thousand, five hundred eighteen".