20955911 has 2 divisors, whose sum is σ = 20955912. Its totient is φ = 20955910.

The previous prime is 20955899. The next prime is 20955929. The reversal of 20955911 is 11955902.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20955911 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (20955971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10477955 + 10477956.

It is an arithmetic number, because the mean of its divisors is an integer number (10477956).

Almost surely, 2^20955911 is an apocalyptic number.

20955911 is a deficient number, since it is larger than the sum of its proper divisors (1).

20955911 is an equidigital number, since it uses as much as digits as its factorization.

20955911 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 4050, while the sum is 32.

The square root of 20955911 is about 4577.7626631358. The cubic root of 20955911 is about 275.6992058398.

Subtracting from 20955911 its reverse (11955902), we obtain a palindrome (9000009).

The spelling of 20955911 in words is "twenty million, nine hundred fifty-five thousand, nine hundred eleven".