21147136 has 40 divisors (see below), whose sum is σ = 42769584. Its totient is φ = 10444800.

The previous prime is 21147127. The next prime is 21147157. The reversal of 21147136 is 63174112.

It is a super-2 number, since 2×21147136² = 894402722004992, which contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21147136.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 52536 + ... + 52936.

Almost surely, 2^21147136 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 21147136, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21384792).

21147136 is an abundant number, since it is smaller than the sum of its proper divisors (21622448).

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

21147136 is an equidigital number, since it uses as much as digits as its factorization.

21147136 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 522 (or 506 counting only the distinct ones).

The product of its digits is 1008, while the sum is 25.

The square root of 21147136 is about 4598.6015265513. The cubic root of 21147136 is about 276.5352631587.

The spelling of 21147136 in words is "twenty-one million, one hundred forty-seven thousand, one hundred thirty-six".