21284488 has 16 divisors (see below), whose sum is σ = 40026780. Its totient is φ = 10610688.

The previous prime is 21284423. The next prime is 21284489. The reversal of 21284488 is 88448212.

It can be written as a sum of positive squares in 2 ways, for example, as 21141604 + 142884 = 4598^2 + 378^2 .

It is a nude number because it is divisible by every one of its digits.

It is not an unprimeable number, because it can be changed into a prime (21284489) 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, 945 + ... + 6592.

Almost surely, 2^21284488 is an apocalyptic number.

It is an amenable number.

21284488 is a deficient number, since it is larger than the sum of its proper divisors (18742292).

21284488 is a wasteful number, since it uses less digits than its factorization.

21284488 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7896 (or 7892 counting only the distinct ones).

The product of its digits is 32768, while the sum is 37.

The square root of 21284488 is about 4613.5114609156. The cubic root of 21284488 is about 277.1326763438.

The spelling of 21284488 in words is "twenty-one million, two hundred eighty-four thousand, four hundred eighty-eight".