20904811 has 2 divisors, whose sum is σ = 20904812. Its totient is φ = 20904810.

The previous prime is 20904803. The next prime is 20904817. The reversal of 20904811 is 11840902.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20904811 - 2³ = 20904803 is a prime.

It is a super-2 number, since 2×20904811² = 874022245891442, which contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (20904817) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10452405 + 10452406.

It is an arithmetic number, because the mean of its divisors is an integer number (10452406).

Almost surely, 2^20904811 is an apocalyptic number.

20904811 is a deficient number, since it is larger than the sum of its proper divisors (1).

20904811 is an equidigital number, since it uses as much as digits as its factorization.

20904811 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 576, while the sum is 25.

The square root of 20904811 is about 4572.1779274215. The cubic root of 20904811 is about 275.4749302783.

The spelling of 20904811 in words is "twenty million, nine hundred four thousand, eight hundred eleven".