20722897 has 8 divisors (see below), whose sum is σ = 22417640. Its totient is φ = 19042560.

The previous prime is 20722873. The next prime is 20722909. The reversal of 20722897 is 79822702.

It can be written as a sum of positive squares in 4 ways, for example, as 6765201 + 13957696 = 2601^2 + 3736^2 .

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 20722897 - 2⁷ = 20722769 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20722837) 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, 504 + ... + 6457.

It is an arithmetic number, because the mean of its divisors is an integer number (2802205).

Almost surely, 2^20722897 is an apocalyptic number.

It is an amenable number.

20722897 is a deficient number, since it is larger than the sum of its proper divisors (1694743).

20722897 is a wasteful number, since it uses less digits than its factorization.

20722897 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7203.

The product of its (nonzero) digits is 28224, while the sum is 37.

The square root of 20722897 is about 4552.2408767551. The cubic root of 20722897 is about 274.6735387717.

It can be divided in two parts, 207 and 22897, that added together give a square (23104 = 152²).

The spelling of 20722897 in words is "twenty million, seven hundred twenty-two thousand, eight hundred ninety-seven".