61666660 has 24 divisors (see below), whose sum is σ = 141273216. Its totient is φ = 22424160.

The previous prime is 61666651. The next prime is 61666681. The reversal of 61666660 is 6666616.

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, 139932 + ... + 140371.

It is an arithmetic number, because the mean of its divisors is an integer number (5886384).

Almost surely, 2^61666660 is an apocalyptic number.

It is an amenable number.

61666660 is an abundant number, since it is smaller than the sum of its proper divisors (79606556).

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

61666660 is a wasteful number, since it uses less digits than its factorization.

61666660 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 280323 (or 280321 counting only the distinct ones).

The product of its (nonzero) digits is 46656, while the sum is 37.

The square root of 61666660 is about 7852.8122351168. The cubic root of 61666660 is about 395.0785722028.

It can be divided in two parts, 61666 and 660, that added together give a palindrome (62326).

The spelling of 61666660 in words is "sixty-one million, six hundred sixty-six thousand, six hundred sixty".