21424699 has 2 divisors, whose sum is σ = 21424700. Its totient is φ = 21424698.

The previous prime is 21424693. The next prime is 21424759. The reversal of 21424699 is 99642412.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21424699 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21424693) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10712349 + 10712350.

It is an arithmetic number, because the mean of its divisors is an integer number (10712350).

Almost surely, 2^21424699 is an apocalyptic number.

21424699 is a deficient number, since it is larger than the sum of its proper divisors (1).

21424699 is an equidigital number, since it uses as much as digits as its factorization.

21424699 is an evil number, because the sum of its binary digits is even.

The product of its digits is 31104, while the sum is 37.

The square root of 21424699 is about 4628.6822098736. The cubic root of 21424699 is about 277.7398796949.

The spelling of 21424699 in words is "twenty-one million, four hundred twenty-four thousand, six hundred ninety-nine".