21370284 has 96 divisors (see below), whose sum is σ = 61716480. Its totient is φ = 6350400.

The previous prime is 21370249. The next prime is 21370333. The reversal of 21370284 is 48207312.

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

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

It is an unprimeable number.

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 31 ways as a sum of consecutive naturals, for example, 43279 + ... + 43769.

It is an arithmetic number, because the mean of its divisors is an integer number (642880).

Almost surely, 2^21370284 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 21370284, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30858240).

21370284 is an abundant number, since it is smaller than the sum of its proper divisors (40346196).

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

21370284 is a wasteful number, since it uses less digits than its factorization.

21370284 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 548 (or 540 counting only the distinct ones).

The product of its (nonzero) digits is 2688, while the sum is 27.

The square root of 21370284 is about 4622.8004499437. The cubic root of 21370284 is about 277.5045433880.

Adding to 21370284 its reverse (48207312), we get a palindrome (69577596).

The spelling of 21370284 in words is "twenty-one million, three hundred seventy thousand, two hundred eighty-four".