21738222 has 24 divisors (see below), whose sum is σ = 51381720. Its totient is φ = 6587280.

The previous prime is 21738221. The next prime is 21738239. The reversal of 21738222 is 22283712.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21738221) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 54697 + ... + 55092.

It is an arithmetic number, because the mean of its divisors is an integer number (2140905).

Almost surely, 2^21738222 is an apocalyptic number.

21738222 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

21738222 is an abundant number, since it is smaller than the sum of its proper divisors (29643498).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

21738222 is a wasteful number, since it uses less digits than its factorization.

21738222 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 109808 (or 109805 counting only the distinct ones).

The product of its digits is 2688, while the sum is 27.

The square root of 21738222 is about 4662.4266214065. The cubic root of 21738222 is about 279.0881133802.

Subtracting 21738222 from its reverse (22283712), we obtain a triangular number (545490 = T₁₀₄₄).

The spelling of 21738222 in words is "twenty-one million, seven hundred thirty-eight thousand, two hundred twenty-two".