22351721 has 16 divisors (see below), whose sum is σ = 26707200. Its totient is φ = 18301248.

The previous prime is 22351711. The next prime is 22351741. The reversal of 22351721 is 12715322.

It is a happy number.

It is not a de Polignac number, because 22351721 - 2¹⁰ = 22350697 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (22351711) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 20375 + ... + 21443.

It is an arithmetic number, because the mean of its divisors is an integer number (1669200).

Almost surely, 2^22351721 is an apocalyptic number.

It is an amenable number.

22351721 is a deficient number, since it is larger than the sum of its proper divisors (4355479).

22351721 is a wasteful number, since it uses less digits than its factorization.

22351721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1208.

The product of its digits is 840, while the sum is 23.

The square root of 22351721 is about 4727.7606749919. The cubic root of 22351721 is about 281.6892818616.

The spelling of 22351721 in words is "twenty-two million, three hundred fifty-one thousand, seven hundred twenty-one".