22720997 has 8 divisors (see below), whose sum is σ = 25130616. Its totient is φ = 20405952.

The previous prime is 22720981. The next prime is 22721021. The reversal of 22720997 is 79902722.

It can be written as a sum of positive squares in 4 ways, for example, as 148996 + 22572001 = 386^2 + 4751^2 .

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 22720997 - 2⁴ = 22720981 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 22720997.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (22720927) 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, 23138 + ... + 24099.

It is an arithmetic number, because the mean of its divisors is an integer number (3141327).

Almost surely, 2^22720997 is an apocalyptic number.

It is an amenable number.

22720997 is a deficient number, since it is larger than the sum of its proper divisors (2409619).

22720997 is a wasteful number, since it uses less digits than its factorization.

22720997 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 47287.

The product of its (nonzero) digits is 31752, while the sum is 38.

The square root of 22720997 is about 4766.6546969547. The cubic root of 22720997 is about 283.2320928564.

The spelling of 22720997 in words is "twenty-two million, seven hundred twenty thousand, nine hundred ninety-seven".