21425311 has 2 divisors, whose sum is σ = 21425312. Its totient is φ = 21425310.

The previous prime is 21425297. The next prime is 21425317. The reversal of 21425311 is 11352412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21425311 - 2¹⁷ = 21294239 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21425317) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10712655 + 10712656.

It is an arithmetic number, because the mean of its divisors is an integer number (10712656).

Almost surely, 2^21425311 is an apocalyptic number.

21425311 is a deficient number, since it is larger than the sum of its proper divisors (1).

21425311 is an equidigital number, since it uses as much as digits as its factorization.

21425311 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 240, while the sum is 19.

The square root of 21425311 is about 4628.7483189303. The cubic root of 21425311 is about 277.7425242312.

Adding to 21425311 its reverse (11352412), we get a palindrome (32777723).

It can be divided in two parts, 21425 and 311, that added together give a triangular number (21736 = T₂₀₈).

The spelling of 21425311 in words is "twenty-one million, four hundred twenty-five thousand, three hundred eleven".