22645721 has 8 divisors (see below), whose sum is σ = 25941120. Its totient is φ = 19365408.

The previous prime is 22645709. The next prime is 22645729. The reversal of 22645721 is 12754622.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 22645721 - 2⁶ = 22645657 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (22645729) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 341 + ... + 6738.

It is an arithmetic number, because the mean of its divisors is an integer number (3242640).

Almost surely, 2^22645721 is an apocalyptic number.

It is an amenable number.

22645721 is a deficient number, since it is larger than the sum of its proper divisors (3295399).

22645721 is an equidigital number, since it uses as much as digits as its factorization.

22645721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7543.

The product of its digits is 6720, while the sum is 29.

The square root of 22645721 is about 4758.7520422901. The cubic root of 22645721 is about 282.9189585942.

The spelling of 22645721 in words is "twenty-two million, six hundred forty-five thousand, seven hundred twenty-one".