21222154 has 16 divisors (see below), whose sum is σ = 34344648. Its totient is φ = 9797632.

The previous prime is 21222143. The next prime is 21222163. The reversal of 21222154 is 45122212.

It can be written as a sum of positive squares in 4 ways, for example, as 21206025 + 16129 = 4605^2 + 127^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4087 + ... + 7690.

Almost surely, 2^21222154 is an apocalyptic number.

21222154 is a deficient number, since it is larger than the sum of its proper divisors (13122494).

21222154 is a wasteful number, since it uses less digits than its factorization.

21222154 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 11849.

The product of its digits is 320, while the sum is 19.

The square root of 21222154 is about 4606.7509157757. The cubic root of 21222154 is about 276.8618738161.

Adding to 21222154 its reverse (45122212), we get a palindrome (66344366).

It can be divided in two parts, 212 and 22154, that added together give a triangular number (22366 = T₂₁₁).

The spelling of 21222154 in words is "twenty-one million, two hundred twenty-two thousand, one hundred fifty-four".