20906969 has 2 divisors, whose sum is σ = 20906970. Its totient is φ = 20906968.

The previous prime is 20906939. The next prime is 20906971. The reversal of 20906969 is 96960902.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14531344 + 6375625 = 3812^2 + 2525^2 .

It is a cyclic number.

It is not a de Polignac number, because 20906969 - 2¹² = 20902873 is a prime.

It is a super-2 number, since 2×20906969² = 874202705533922, which contains 22 as substring.

Together with 20906971, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20906929) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10453484 + 10453485.

It is an arithmetic number, because the mean of its divisors is an integer number (10453485).

Almost surely, 2^20906969 is an apocalyptic number.

It is an amenable number.

20906969 is a deficient number, since it is larger than the sum of its proper divisors (1).

20906969 is an equidigital number, since it uses as much as digits as its factorization.

20906969 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 52488, while the sum is 41.

The square root of 20906969 is about 4572.4139138971. The cubic root of 20906969 is about 275.4844090285.

The spelling of 20906969 in words is "twenty million, nine hundred six thousand, nine hundred sixty-nine".