166681580505 has 32 divisors (see below), whose sum is σ = 290954972160. Its totient is φ = 80809798080.

The previous prime is 166681580491. The next prime is 166681580537. The reversal of 166681580505 is 505085186661.

It is a happy number.

It is not a de Polignac number, because 166681580505 - 2⁴ = 166681580489 is a prime.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 3464706 + ... + 3512484.

It is an arithmetic number, because the mean of its divisors is an integer number (9092342880).

Almost surely, 2^166681580505 is an apocalyptic number.

166681580505 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

166681580505 is a deficient number, since it is larger than the sum of its proper divisors (124273391655).

166681580505 is a wasteful number, since it uses less digits than its factorization.

166681580505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 68941.

The product of its (nonzero) digits is 1728000, while the sum is 51.

The spelling of 166681580505 in words is "one hundred sixty-six billion, six hundred eighty-one million, five hundred eighty thousand, five hundred five".