20928811 has 2 divisors, whose sum is σ = 20928812. Its totient is φ = 20928810.

The previous prime is 20928793. The next prime is 20928821. The reversal of 20928811 is 11882902.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20928811 - 2¹⁷ = 20797739 is a prime.

It is not a weakly prime, because it can be changed into another prime (20928821) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10464405 + 10464406.

It is an arithmetic number, because the mean of its divisors is an integer number (10464406).

Almost surely, 2^20928811 is an apocalyptic number.

20928811 is a deficient number, since it is larger than the sum of its proper divisors (1).

20928811 is an equidigital number, since it uses as much as digits as its factorization.

20928811 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 2304, while the sum is 31.

The square root of 20928811 is about 4574.8017443382. The cubic root of 20928811 is about 275.5803106433.

The spelling of 20928811 in words is "twenty million, nine hundred twenty-eight thousand, eight hundred eleven".