21124699 has 2 divisors, whose sum is σ = 21124700. Its totient is φ = 21124698.

The previous prime is 21124681. The next prime is 21124703. The reversal of 21124699 is 99642112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21124699 - 2¹⁷ = 20993627 is a prime.

It is not a weakly prime, because it can be changed into another prime (21124619) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10562349 + 10562350.

It is an arithmetic number, because the mean of its divisors is an integer number (10562350).

Almost surely, 2^21124699 is an apocalyptic number.

21124699 is a deficient number, since it is larger than the sum of its proper divisors (1).

21124699 is an equidigital number, since it uses as much as digits as its factorization.

21124699 is an evil number, because the sum of its binary digits is even.

The product of its digits is 7776, while the sum is 34.

The square root of 21124699 is about 4596.1613331127. The cubic root of 21124699 is about 276.4374277300.

The spelling of 21124699 in words is "twenty-one million, one hundred twenty-four thousand, six hundred ninety-nine".