166613650621 has 32 divisors (see below), whose sum is σ = 188930506752. Its totient is φ = 145563600000.

The previous prime is 166613650579. The next prime is 166613650639. The reversal of 166613650621 is 126056316661.

It is not a de Polignac number, because 166613650621 - 2²³ = 166605262013 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166613650121) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 29797536 + ... + 29803126.

It is an arithmetic number, because the mean of its divisors is an integer number (5904078336).

Almost surely, 2^166613650621 is an apocalyptic number.

166613650621 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

166613650621 is a deficient number, since it is larger than the sum of its proper divisors (22316856131).

166613650621 is a wasteful number, since it uses less digits than its factorization.

166613650621 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6225.

The product of its (nonzero) digits is 233280, while the sum is 43.

The spelling of 166613650621 in words is "one hundred sixty-six billion, six hundred thirteen million, six hundred fifty thousand, six hundred twenty-one".