21683228 has 24 divisors (see below), whose sum is σ = 45918432. Its totient is φ = 8745984.

The previous prime is 21683203. The next prime is 21683287. The reversal of 21683228 is 82238612.

21683228 = 1757² + 1758² + ... + 1763².

It is a junction number, because it is equal to n+sod(n) for n = 21683194 and 21683203.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 22301 + ... + 23252.

It is an arithmetic number, because the mean of its divisors is an integer number (1913268).

Almost surely, 2^21683228 is an apocalyptic number.

21683228 is a gapful number since it is divisible by the number (28) formed by its first and last digit.

It is an amenable number.

21683228 is an abundant number, since it is smaller than the sum of its proper divisors (24235204).

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

21683228 is a wasteful number, since it uses less digits than its factorization.

21683228 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45581 (or 45579 counting only the distinct ones).

The product of its digits is 9216, while the sum is 32.

The square root of 21683228 is about 4656.5253140083. The cubic root of 21683228 is about 278.8525661693.

It can be divided in two parts, 216832 and 28, that multiplied together give a square (6071296 = 2464²).

The spelling of 21683228 in words is "twenty-one million, six hundred eighty-three thousand, two hundred twenty-eight".