166718721720 has 32 divisors (see below), whose sum is σ = 500156165520. Its totient is φ = 44458325760.

The previous prime is 166718721691. The next prime is 166718721721. The reversal of 166718721720 is 27127817661.

It is a self number, because there is not a number n which added to its sum of digits gives 166718721720.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166718721721) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 694661221 + ... + 694661460.

Almost surely, 2^166718721720 is an apocalyptic number.

166718721720 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

166718721720 is an abundant number, since it is smaller than the sum of its proper divisors (333437443800).

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

166718721720 is a wasteful number, since it uses less digits than its factorization.

166718721720 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1389322695 (or 1389322691 counting only the distinct ones).

The product of its (nonzero) digits is 395136, while the sum is 48.

The spelling of 166718721720 in words is "one hundred sixty-six billion, seven hundred eighteen million, seven hundred twenty-one thousand, seven hundred twenty".