21634799 has 2 divisors, whose sum is σ = 21634800. Its totient is φ = 21634798.

The previous prime is 21634741. The next prime is 21634801. The reversal of 21634799 is 99743612.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21634799 - 2¹⁶ = 21569263 is a prime.

It is a Sophie Germain prime.

Together with 21634801, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21634729) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10817399 + 10817400.

It is an arithmetic number, because the mean of its divisors is an integer number (10817400).

Almost surely, 2^21634799 is an apocalyptic number.

21634799 is a deficient number, since it is larger than the sum of its proper divisors (1).

21634799 is an equidigital number, since it uses as much as digits as its factorization.

21634799 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 81648, while the sum is 41.

The square root of 21634799 is about 4651.3222851142. The cubic root of 21634799 is about 278.6448077818.

The spelling of 21634799 in words is "twenty-one million, six hundred thirty-four thousand, seven hundred ninety-nine".