21634699 has 2 divisors, whose sum is σ = 21634700. Its totient is φ = 21634698.

The previous prime is 21634663. The next prime is 21634729. The reversal of 21634699 is 99643612.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21634699 - 2¹¹ = 21632651 is a prime.

It is not a weakly prime, because it can be changed into another prime (21634649) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10817349 + 10817350.

It is an arithmetic number, because the mean of its divisors is an integer number (10817350).

Almost surely, 2^21634699 is an apocalyptic number.

21634699 is a deficient number, since it is larger than the sum of its proper divisors (1).

21634699 is an equidigital number, since it uses as much as digits as its factorization.

21634699 is an evil number, because the sum of its binary digits is even.

The product of its digits is 69984, while the sum is 40.

The square root of 21634699 is about 4651.3115354704. The cubic root of 21634699 is about 278.6443784654.

The spelling of 21634699 in words is "twenty-one million, six hundred thirty-four thousand, six hundred ninety-nine".