21223654 has 16 divisors (see below), whose sum is σ = 33094656. Its totient is φ = 10197000.

The previous prime is 21223651. The next prime is 21223661. The reversal of 21223654 is 45632212.

It is a super-2 number, since 2×21223654² = 900886978223432, which contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21223651) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8229 + ... + 10495.

It is an arithmetic number, because the mean of its divisors is an integer number (2068416).

Almost surely, 2^21223654 is an apocalyptic number.

21223654 is a deficient number, since it is larger than the sum of its proper divisors (11871002).

21223654 is a wasteful number, since it uses less digits than its factorization.

21223654 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2451.

The product of its digits is 2880, while the sum is 25.

The square root of 21223654 is about 4606.9137174469. The cubic root of 21223654 is about 276.8683966072.

Adding to 21223654 its reverse (45632212), we get a palindrome (66855866).

It can be divided in two parts, 2122 and 3654, that added together give a square (5776 = 76²).

The spelling of 21223654 in words is "twenty-one million, two hundred twenty-three thousand, six hundred fifty-four".