21548228 has 12 divisors (see below), whose sum is σ = 40610220. Its totient is φ = 9945312.

The previous prime is 21548227. The next prime is 21548237. The reversal of 21548228 is 82284512.

It can be written as a sum of positive squares in 2 ways, for example, as 3161284 + 18386944 = 1778^2 + 4288^2 .

It is a super-2 number, since 2×21548228² = 928652259879968, which contains 22 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21548194 and 21548203.

It is not an unprimeable number, because it can be changed into a prime (21548221) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 207143 + ... + 207246.

It is an arithmetic number, because the mean of its divisors is an integer number (3384185).

Almost surely, 2^21548228 is an apocalyptic number.

It is an amenable number.

21548228 is a deficient number, since it is larger than the sum of its proper divisors (19061992).

21548228 is a wasteful number, since it uses less digits than its factorization.

21548228 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 414406 (or 414404 counting only the distinct ones).

The product of its digits is 10240, while the sum is 32.

The square root of 21548228 is about 4642.0068935752. The cubic root of 21548228 is about 278.2726479941.

The spelling of 21548228 in words is "twenty-one million, five hundred forty-eight thousand, two hundred twenty-eight".