21283020 has 96 divisors (see below), whose sum is σ = 72253440. Its totient is φ = 5158080.

The previous prime is 21283001. The next prime is 21283033. The reversal of 21283020 is 2038212.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a junction number, because it is equal to n+sod(n) for n = 21282984 and 21283002.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 4149 + ... + 7731.

It is an arithmetic number, because the mean of its divisors is an integer number (752640).

Almost surely, 2^21283020 is an apocalyptic number.

21283020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21283020, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36126720).

21283020 is an abundant number, since it is smaller than the sum of its proper divisors (50970420).

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

21283020 is a wasteful number, since it uses less digits than its factorization.

21283020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3612 (or 3604 counting only the distinct ones).

The product of its (nonzero) digits is 192, while the sum is 18.

The square root of 21283020 is about 4613.3523602690. The cubic root of 21283020 is about 277.1263048787.

The spelling of 21283020 in words is "twenty-one million, two hundred eighty-three thousand, twenty".