21446236 has 48 divisors (see below), whose sum is σ = 44670976. Its totient is φ = 8817984.

The previous prime is 21446233. The next prime is 21446237. The reversal of 21446236 is 63264412.

It is a Harshad number since it is a multiple of its sum of digits (28).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21446233) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 131491 + ... + 131653.

Almost surely, 2^21446236 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 21446236, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22335488).

21446236 is an abundant number, since it is smaller than the sum of its proper divisors (23224740).

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

21446236 is a wasteful number, since it uses less digits than its factorization.

21446236 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 338 (or 336 counting only the distinct ones).

The product of its digits is 6912, while the sum is 28.

The square root of 21446236 is about 4631.0080975960. The cubic root of 21446236 is about 277.8329137605.

The spelling of 21446236 in words is "twenty-one million, four hundred forty-six thousand, two hundred thirty-six".