21450799 has 2 divisors, whose sum is σ = 21450800. Its totient is φ = 21450798.

The previous prime is 21450797. The next prime is 21450809. The reversal of 21450799 is 99705412.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21450799 - 2¹ = 21450797 is a prime.

Together with 21450797, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21450797) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10725399 + 10725400.

It is an arithmetic number, because the mean of its divisors is an integer number (10725400).

Almost surely, 2^21450799 is an apocalyptic number.

21450799 is a deficient number, since it is larger than the sum of its proper divisors (1).

21450799 is an equidigital number, since it uses as much as digits as its factorization.

21450799 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 22680, while the sum is 37.

The square root of 21450799 is about 4631.5007287055. The cubic root of 21450799 is about 277.8526167003.

The spelling of 21450799 in words is "twenty-one million, four hundred fifty thousand, seven hundred ninety-nine".