21222799 has 4 divisors (see below), whose sum is σ = 22855336. Its totient is φ = 19590264.

The previous prime is 21222787. The next prime is 21222847. The reversal of 21222799 is 99722212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21222799 - 2⁷ = 21222671 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21222739) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 816249 + ... + 816274.

It is an arithmetic number, because the mean of its divisors is an integer number (5713834).

Almost surely, 2^21222799 is an apocalyptic number.

21222799 is a deficient number, since it is larger than the sum of its proper divisors (1632537).

21222799 is a wasteful number, since it uses less digits than its factorization.

21222799 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1632536.

The product of its digits is 9072, while the sum is 34.

The square root of 21222799 is about 4606.8209211993. The cubic root of 21222799 is about 276.8646786539.

The spelling of 21222799 in words is "twenty-one million, two hundred twenty-two thousand, seven hundred ninety-nine".