21484820 has 96 divisors (see below), whose sum is σ = 55883520. Its totient is φ = 6773760.

The previous prime is 21484819. The next prime is 21484831. The reversal of 21484820 is 2848412.

It is a congruent number.

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, 108962 + ... + 109158.

It is an arithmetic number, because the mean of its divisors is an integer number (582120).

Almost surely, 2^21484820 is an apocalyptic number.

21484820 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 21484820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27941760).

21484820 is an abundant number, since it is smaller than the sum of its proper divisors (34398700).

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

21484820 is a wasteful number, since it uses less digits than its factorization.

21484820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 273 (or 271 counting only the distinct ones).

The product of its (nonzero) digits is 4096, while the sum is 29.

The square root of 21484820 is about 4635.1720572164. The cubic root of 21484820 is about 277.9994306701. Note that the first 3 decimals are identical.

The spelling of 21484820 in words is "twenty-one million, four hundred eighty-four thousand, eight hundred twenty".