61217115666 has 32 divisors (see below), whose sum is σ = 140525394048. Its totient is φ = 17415534720.

The previous prime is 61217115647. The next prime is 61217115727. The reversal of 61217115666 is 66651171216.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3118005 + ... + 3137576.

It is an arithmetic number, because the mean of its divisors is an integer number (4391418564).

Almost surely, 2^61217115666 is an apocalyptic number.

61217115666 is an abundant number, since it is smaller than the sum of its proper divisors (79308278382).

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

61217115666 is a wasteful number, since it uses less digits than its factorization.

61217115666 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6255826.

The product of its digits is 90720, while the sum is 42.

The spelling of 61217115666 in words is "sixty-one billion, two hundred seventeen million, one hundred fifteen thousand, six hundred sixty-six".