21366356 has 48 divisors (see below), whose sum is σ = 43642368. Its totient is φ = 9055200.

The previous prime is 21366343. The next prime is 21366377. The reversal of 21366356 is 65366312.

It is a Smith number, since the sum of its digits (32) coincides with the sum of the digits of its prime factors.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 43271 + ... + 43761.

It is an arithmetic number, because the mean of its divisors is an integer number (909216).

Almost surely, 2^21366356 is an apocalyptic number.

It is an amenable number.

21366356 is an abundant number, since it is smaller than the sum of its proper divisors (22276012).

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

21366356 is a wasteful number, since it uses less digits than its factorization.

21366356 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 572 (or 570 counting only the distinct ones).

The product of its digits is 19440, while the sum is 32.

The square root of 21366356 is about 4622.3755797209. The cubic root of 21366356 is about 277.4875399540.

The spelling of 21366356 in words is "twenty-one million, three hundred sixty-six thousand, three hundred fifty-six".