21064291 has 2 divisors, whose sum is σ = 21064292. Its totient is φ = 21064290.

The previous prime is 21064273. The next prime is 21064301. The reversal of 21064291 is 19246012.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21064291 - 2⁵ = 21064259 is a prime.

It is equal to p_1333816 and since 21064291 and 1333816 have the same sum of digits, it is a Honaker prime.

It is not a weakly prime, because it can be changed into another prime (21064231) 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, 10532145 + 10532146.

It is an arithmetic number, because the mean of its divisors is an integer number (10532146).

Almost surely, 2^21064291 is an apocalyptic number.

21064291 is a deficient number, since it is larger than the sum of its proper divisors (1).

21064291 is an equidigital number, since it uses as much as digits as its factorization.

21064291 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 864, while the sum is 25.

The square root of 21064291 is about 4589.5850574970. The cubic root of 21064291 is about 276.1736768329.

The spelling of 21064291 in words is "twenty-one million, sixty-four thousand, two hundred ninety-one".