21248807 has 2 divisors, whose sum is σ = 21248808. Its totient is φ = 21248806.

The previous prime is 21248779. The next prime is 21248819. The reversal of 21248807 is 70884212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21248807 - 2⁶ = 21248743 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21248107) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10624403 + 10624404.

It is an arithmetic number, because the mean of its divisors is an integer number (10624404).

Almost surely, 2^21248807 is an apocalyptic number.

21248807 is a deficient number, since it is larger than the sum of its proper divisors (1).

21248807 is an equidigital number, since it uses as much as digits as its factorization.

21248807 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7168, while the sum is 32.

The square root of 21248807 is about 4609.6428278122. The cubic root of 21248807 is about 276.9777293585.

The spelling of 21248807 in words is "twenty-one million, two hundred forty-eight thousand, eight hundred seven".