20722769 has 2 divisors, whose sum is σ = 20722770. Its totient is φ = 20722768.

The previous prime is 20722687. The next prime is 20722781. The reversal of 20722769 is 96722702.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14025025 + 6697744 = 3745^2 + 2588^2 .

It is a cyclic number.

It is not a de Polignac number, because 20722769 - 2¹⁶ = 20657233 is a prime.

It is a super-2 number, since 2×20722769² = 858866310054722, which contains 22 as substring.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (20722799) 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 as a sum of consecutive naturals, namely, 10361384 + 10361385.

It is an arithmetic number, because the mean of its divisors is an integer number (10361385).

Almost surely, 2^20722769 is an apocalyptic number.

It is an amenable number.

20722769 is a deficient number, since it is larger than the sum of its proper divisors (1).

20722769 is an equidigital number, since it uses as much as digits as its factorization.

20722769 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 21168, while the sum is 35.

The square root of 20722769 is about 4552.2268177234. The cubic root of 20722769 is about 274.6729732413.

The spelling of 20722769 in words is "twenty million, seven hundred twenty-two thousand, seven hundred sixty-nine".