21266807 has 2 divisors, whose sum is σ = 21266808. Its totient is φ = 21266806.

The previous prime is 21266797. The next prime is 21266849. The reversal of 21266807 is 70866212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21266807 - 2⁸ = 21266551 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21266867) 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, 10633403 + 10633404.

It is an arithmetic number, because the mean of its divisors is an integer number (10633404).

Almost surely, 2^21266807 is an apocalyptic number.

21266807 is a deficient number, since it is larger than the sum of its proper divisors (1).

21266807 is an equidigital number, since it uses as much as digits as its factorization.

21266807 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8064, while the sum is 32.

The square root of 21266807 is about 4611.5948434354. The cubic root of 21266807 is about 277.0559171522.

The spelling of 21266807 in words is "twenty-one million, two hundred sixty-six thousand, eight hundred seven".