21222454 has 16 divisors (see below), whose sum is σ = 34799040. Its totient is φ = 9626760.

The previous prime is 21222433. The next prime is 21222469. The reversal of 21222454 is 45422212.

It is a Harshad number since it is a multiple of its sum of digits (22).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 18337 + ... + 19459.

It is an arithmetic number, because the mean of its divisors is an integer number (2174940).

Almost surely, 2^21222454 is an apocalyptic number.

21222454 is a deficient number, since it is larger than the sum of its proper divisors (13576586).

21222454 is a wasteful number, since it uses less digits than its factorization.

21222454 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1995.

The product of its digits is 1280, while the sum is 22.

The square root of 21222454 is about 4606.7834765702. The cubic root of 21222454 is about 276.8631783989.

Adding to 21222454 its reverse (45422212), we get a palindrome (66644666).

The spelling of 21222454 in words is "twenty-one million, two hundred twenty-two thousand, four hundred fifty-four".