21283488 has 72 divisors (see below), whose sum is σ = 61483968. Its totient is φ = 6982272.

The previous prime is 21283463. The next prime is 21283501. The reversal of 21283488 is 88438212.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (72).

It is a super-2 number, since 2×21283488² = 905973722892288, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

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

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 18745 + ... + 19847.

It is an arithmetic number, because the mean of its divisors is an integer number (853944).

Almost surely, 2^21283488 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21283488, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30741984).

21283488 is an abundant number, since it is smaller than the sum of its proper divisors (40200480).

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

21283488 is a wasteful number, since it uses less digits than its factorization.

21283488 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1186 (or 1175 counting only the distinct ones).

The product of its digits is 24576, while the sum is 36.

The square root of 21283488 is about 4613.4030823244. The cubic root of 21283488 is about 277.1283361405.

The spelling of 21283488 in words is "twenty-one million, two hundred eighty-three thousand, four hundred eighty-eight".