21066448 has 20 divisors (see below), whose sum is σ = 43956388. Its totient is φ = 9722880.

The previous prime is 21066443. The next prime is 21066449. The reversal of 21066448 is 84466012.

It can be written as a sum of positive squares in 2 ways, for example, as 1459264 + 19607184 = 1208^2 + 4428^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21066443) 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, 50433 + ... + 50848.

Almost surely, 2^21066448 is an apocalyptic number.

It is an amenable number.

21066448 is an abundant number, since it is smaller than the sum of its proper divisors (22889940).

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

21066448 is a wasteful number, since it uses less digits than its factorization.

21066448 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 101302 (or 101296 counting only the distinct ones).

The product of its (nonzero) digits is 9216, while the sum is 31.

The square root of 21066448 is about 4589.8200400451. The cubic root of 21066448 is about 276.1831033119.

The spelling of 21066448 in words is "twenty-one million, sixty-six thousand, four hundred forty-eight".