21284046 has 60 divisors (see below), whose sum is σ = 54905928. Its totient is φ = 6036768.

The previous prime is 21284041. The next prime is 21284093. The reversal of 21284046 is 64048212.

It is a super-2 number, since 2×21284046² = 906021228260232, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21284041) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 29 ways as a sum of consecutive naturals, for example, 155290 + ... + 155426.

Almost surely, 2^21284046 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21284046, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (27452964).

21284046 is an abundant number, since it is smaller than the sum of its proper divisors (33621882).

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

21284046 is an equidigital number, since it uses as much as digits as its factorization.

21284046 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 295 (or 149 counting only the distinct ones).

The product of its (nonzero) digits is 3072, while the sum is 27.

The square root of 21284046 is about 4613.4635578923. The cubic root of 21284046 is about 277.1307579907.

The spelling of 21284046 in words is "twenty-one million, two hundred eighty-four thousand, forty-six".