122166721 has 4 divisors (see below), whose sum is σ = 122230192. Its totient is φ = 122103252.

The previous prime is 122166689. The next prime is 122166767. The reversal of 122166721 is 127661221.

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: 127661221 = 83 ⋅1538087.

It is a cyclic number.

It is not a de Polignac number, because 122166721 - 2⁵ = 122166689 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 122166721.

It is not an unprimeable number, because it can be changed into a prime (122166791) 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, 28755 + ... + 32728.

It is an arithmetic number, because the mean of its divisors is an integer number (30557548).

Almost surely, 2^122166721 is an apocalyptic number.

It is an amenable number.

122166721 is a deficient number, since it is larger than the sum of its proper divisors (63471).

122166721 is an equidigital number, since it uses as much as digits as its factorization.

122166721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 63470.

The product of its digits is 2016, while the sum is 28.

The square root of 122166721 is about 11052.9055456020. The cubic root of 122166721 is about 496.1933876162.

The spelling of 122166721 in words is "one hundred twenty-two million, one hundred sixty-six thousand, seven hundred twenty-one".