166362721 has 4 divisors (see below), whose sum is σ = 190128832. Its totient is φ = 142596612.

The previous prime is 166362701. The next prime is 166362787. The reversal of 166362721 is 127263661.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 127263661 = 7 ⋅18180523.

It is a cyclic number.

It is not a de Polignac number, because 166362721 - 2⁷ = 166362593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (166362701) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11883045 + ... + 11883058.

It is an arithmetic number, because the mean of its divisors is an integer number (47532208).

Almost surely, 2^166362721 is an apocalyptic number.

It is an amenable number.

166362721 is a deficient number, since it is larger than the sum of its proper divisors (23766111).

166362721 is an equidigital number, since it uses as much as digits as its factorization.

166362721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23766110.

The product of its digits is 18144, while the sum is 34.

The square root of 166362721 is about 12898.1673504417. The cubic root of 166362721 is about 549.9864690886.

The spelling of 166362721 in words is "one hundred sixty-six million, three hundred sixty-two thousand, seven hundred twenty-one".