20920811 has 2 divisors, whose sum is σ = 20920812. Its totient is φ = 20920810.

The previous prime is 20920807. The next prime is 20920819. The reversal of 20920811 is 11802902.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 20920811 - 2² = 20920807 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (20920819) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10460405 + 10460406.

It is an arithmetic number, because the mean of its divisors is an integer number (10460406).

Almost surely, 2^20920811 is an apocalyptic number.

20920811 is a deficient number, since it is larger than the sum of its proper divisors (1).

20920811 is an equidigital number, since it uses as much as digits as its factorization.

20920811 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 288, while the sum is 23.

The square root of 20920811 is about 4573.9273059374. The cubic root of 20920811 is about 275.5451928106.

The spelling of 20920811 in words is "twenty million, nine hundred twenty thousand, eight hundred eleven".