166837795621 has 8 divisors (see below), whose sum is σ = 190743013760. Its totient is φ = 142950389328.

The previous prime is 166837795603. The next prime is 166837795633. The reversal of 166837795621 is 126597738661.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 166837795621 - 2⁵ = 166837795589 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 166837795621.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (166837795021) 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, 4432881 + ... + 4470358.

It is an arithmetic number, because the mean of its divisors is an integer number (23842876720).

Almost surely, 2^166837795621 is an apocalyptic number.

It is an amenable number.

166837795621 is a deficient number, since it is larger than the sum of its proper divisors (23905218139).

166837795621 is an equidigital number, since it uses as much as digits as its factorization.

166837795621 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8905923.

The product of its digits is 22861440, while the sum is 61.

The spelling of 166837795621 in words is "one hundred sixty-six billion, eight hundred thirty-seven million, seven hundred ninety-five thousand, six hundred twenty-one".