20722249 has 6 divisors (see below), whose sum is σ = 21071310. Its totient is φ = 20378880.

The previous prime is 20722237. The next prime is 20722277. The reversal of 20722249 is 94222702.

It can be written as a sum of positive squares in 3 ways, for example, as 2913849 + 17808400 = 1707^2 + 4220^2 .

It is not a de Polignac number, because 20722249 - 2⁹ = 20721737 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20722349) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 937 + ... + 6505.

It is an arithmetic number, because the mean of its divisors is an integer number (3511885).

Almost surely, 2^20722249 is an apocalyptic number.

It is an amenable number.

20722249 is a deficient number, since it is larger than the sum of its proper divisors (349061).

20722249 is an frugal number, since it uses more digits than its factorization.

20722249 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5691 (or 5630 counting only the distinct ones).

The product of its (nonzero) digits is 4032, while the sum is 28.

The square root of 20722249 is about 4552.1697024606. The cubic root of 20722249 is about 274.6706757500.

The spelling of 20722249 in words is "twenty million, seven hundred twenty-two thousand, two hundred forty-nine".