21747222 has 24 divisors (see below), whose sum is σ = 53850576. Its totient is φ = 6213456.

The previous prime is 21747221. The next prime is 21747227. The reversal of 21747222 is 22274712.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21747221) 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 11 ways as a sum of consecutive naturals, for example, 86173 + ... + 86424.

It is an arithmetic number, because the mean of its divisors is an integer number (2243774).

Almost surely, 2^21747222 is an apocalyptic number.

21747222 is an abundant number, since it is smaller than the sum of its proper divisors (32103354).

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

21747222 is a wasteful number, since it uses less digits than its factorization.

21747222 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 172612 (or 172609 counting only the distinct ones).

The product of its digits is 3136, while the sum is 27.

The square root of 21747222 is about 4663.3916841715. The cubic root of 21747222 is about 279.1266238351.

The spelling of 21747222 in words is "twenty-one million, seven hundred forty-seven thousand, two hundred twenty-two".