21054811 has 2 divisors, whose sum is σ = 21054812. Its totient is φ = 21054810.

The previous prime is 21054791. The next prime is 21054827. The reversal of 21054811 is 11845012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21054811 - 2⁵ = 21054779 is a prime.

It is not a weakly prime, because it can be changed into another prime (21054851) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10527405 + 10527406.

It is an arithmetic number, because the mean of its divisors is an integer number (10527406).

Almost surely, 2^21054811 is an apocalyptic number.

21054811 is a deficient number, since it is larger than the sum of its proper divisors (1).

21054811 is an equidigital number, since it uses as much as digits as its factorization.

21054811 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 320, while the sum is 22.

The square root of 21054811 is about 4588.5521681681. The cubic root of 21054811 is about 276.1322398924.

Adding to 21054811 its reverse (11845012), we get a palindrome (32899823).

The spelling of 21054811 in words is "twenty-one million, fifty-four thousand, eight hundred eleven".