20820769 has 2 divisors, whose sum is σ = 20820770. Its totient is φ = 20820768.

The previous prime is 20820763. The next prime is 20820781. The reversal of 20820769 is 96702802.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 14630625 + 6190144 = 3825^2 + 2488^2 .

It is a cyclic number.

It is not a de Polignac number, because 20820769 - 2¹³ = 20812577 is a prime.

It is a super-2 number, since 2×20820769² = 867008843502722, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20820763) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10410384 + 10410385.

It is an arithmetic number, because the mean of its divisors is an integer number (10410385).

Almost surely, 2^20820769 is an apocalyptic number.

It is an amenable number.

20820769 is a deficient number, since it is larger than the sum of its proper divisors (1).

20820769 is an equidigital number, since it uses as much as digits as its factorization.

20820769 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 12096, while the sum is 34.

The square root of 20820769 is about 4562.9780845408. The cubic root of 20820769 is about 275.1052775980.

The spelling of 20820769 in words is "twenty million, eight hundred twenty thousand, seven hundred sixty-nine".