722121 has 4 divisors (see below), whose sum is σ = 962832. Its totient is φ = 481412.

The previous prime is 722119. The next prime is 722123. The reversal of 722121 is 121227.

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.

It is an interprime number because it is at equal distance from previous prime (722119) and next prime (722123).

It is a cyclic number.

It is not a de Polignac number, because 722121 - 2¹ = 722119 is a prime.

It is a D-number.

It is a self number, because there is not a number n which added to its sum of digits gives 722121.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 722121.

It is not an unprimeable number, because it can be changed into a prime (722123) 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, 120351 + ... + 120356.

It is an arithmetic number, because the mean of its divisors is an integer number (240708).

2⁷²²¹²¹ is an apocalyptic number.

It is an amenable number.

722121 is a deficient number, since it is larger than the sum of its proper divisors (240711).

722121 is a wasteful number, since it uses less digits than its factorization.

722121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 240710.

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

The square root of 722121 is about 849.7770295789. Note that the first 3 decimals coincide. The cubic root of 722121 is about 89.7160184614.

Adding to 722121 its reverse (121227), we get a palindrome (843348).

The spelling of 722121 in words is "seven hundred twenty-two thousand, one hundred twenty-one", and thus it is an iban number.