122721 has 8 divisors (see below), whose sum is σ = 172320. Its totient is φ = 77472.

The previous prime is 122719. The next prime is 122741. The reversal of 122721 is 127221.

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

It is not a de Polignac number, because 122721 - 2¹ = 122719 is a prime.

It is an Ulam number.

It is a self number, because there is not a number n which added to its sum of digits gives 122721.

It is not an unprimeable number, because it can be changed into a prime (122701) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1020 + ... + 1133.

It is an arithmetic number, because the mean of its divisors is an integer number (21540).

2¹²²⁷²¹ is an apocalyptic number.

It is an amenable number.

122721 is a deficient number, since it is larger than the sum of its proper divisors (49599).

122721 is a wasteful number, since it uses less digits than its factorization.

122721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2175.

The product of its digits is 56, while the sum is 15.

The square root of 122721 is about 350.3155720204. The cubic root of 122721 is about 49.6942676989.

Adding to 122721 its reverse (127221), we get a palindrome (249942).

It can be divided in two parts, 1 and 22721, that added together give a palindrome (22722).

The spelling of 122721 in words is "one hundred twenty-two thousand, seven hundred twenty-one", and thus it is an iban number.