21227712 has 168 divisors, whose sum is σ = 67421760. Its totient is φ = 5829120.

The previous prime is 21227711. The next prime is 21227753. The reversal of 21227712 is 21772212.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is not an unprimeable number, because it can be changed into a prime (21227711) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 922933 + ... + 922955.

It is an arithmetic number, because the mean of its divisors is an integer number (401320).

Almost surely, 2^21227712 is an apocalyptic number.

21227712 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21227712, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (33710880).

21227712 is an abundant number, since it is smaller than the sum of its proper divisors (46194048).

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

21227712 is a wasteful number, since it uses less digits than its factorization.

21227712 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 91 (or 58 counting only the distinct ones).

The product of its digits is 784, while the sum is 24.

The square root of 21227712 is about 4607.3541214020. The cubic root of 21227712 is about 276.8860413909.

21227712 divided by its sum of digits (24) gives a palindrome (884488).

Adding to 21227712 its reverse (21772212), we get a palindrome (42999924).

The spelling of 21227712 in words is "twenty-one million, two hundred twenty-seven thousand, seven hundred twelve".