21496399 has 2 divisors, whose sum is σ = 21496400. Its totient is φ = 21496398.

The previous prime is 21496373. The next prime is 21496417. The reversal of 21496399 is 99369412.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21496399 - 2¹⁹ = 20972111 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21496309) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10748199 + 10748200.

It is an arithmetic number, because the mean of its divisors is an integer number (10748200).

Almost surely, 2^21496399 is an apocalyptic number.

21496399 is a deficient number, since it is larger than the sum of its proper divisors (1).

21496399 is an equidigital number, since it uses as much as digits as its factorization.

21496399 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 104976, while the sum is 43.

The square root of 21496399 is about 4636.4209256710. The cubic root of 21496399 is about 278.0493632474.

The spelling of 21496399 in words is "twenty-one million, four hundred ninety-six thousand, three hundred ninety-nine".