21382356 has 12 divisors (see below), whose sum is σ = 49892192. Its totient is φ = 7127448.

The previous prime is 21382349. The next prime is 21382369. The reversal of 21382356 is 65328312.

It is a tau number, because it is divible by the number of its divisors (12).

It is a super-2 number, since 2×21382356² = 914410296221472, which contains 22 as substring.

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, 890920 + ... + 890943.

Almost surely, 2^21382356 is an apocalyptic number.

It is an amenable number.

21382356 is an abundant number, since it is smaller than the sum of its proper divisors (28509836).

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

21382356 is a wasteful number, since it uses less digits than its factorization.

21382356 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1781870 (or 1781868 counting only the distinct ones).

The product of its digits is 8640, while the sum is 30.

The square root of 21382356 is about 4624.1059676439. The cubic root of 21382356 is about 277.5567873394.

The spelling of 21382356 in words is "twenty-one million, three hundred eighty-two thousand, three hundred fifty-six".