21248651 has 2 divisors, whose sum is σ = 21248652. Its totient is φ = 21248650.

The previous prime is 21248641. The next prime is 21248659. The reversal of 21248651 is 15684212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21248651 - 2⁶ = 21248587 is a prime.

It is a Sophie Germain prime.

It is not a weakly prime, because it can be changed into another prime (21248659) 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, 10624325 + 10624326.

It is an arithmetic number, because the mean of its divisors is an integer number (10624326).

Almost surely, 2^21248651 is an apocalyptic number.

21248651 is a deficient number, since it is larger than the sum of its proper divisors (1).

21248651 is an equidigital number, since it uses as much as digits as its factorization.

21248651 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3840, while the sum is 29.

The square root of 21248651 is about 4609.6259067304. The cubic root of 21248651 is about 276.9770515380.

The spelling of 21248651 in words is "twenty-one million, two hundred forty-eight thousand, six hundred fifty-one".