21272356 has 12 divisors (see below), whose sum is σ = 42544768. Its totient is φ = 9116712.

The previous prime is 21272351. The next prime is 21272357. The reversal of 21272356 is 65327212.

21272356 is an admirable number.

It is a Harshad number since it is a multiple of its sum of digits (28), and also a Moran number because the ratio is a prime number: 759727 = 21272356 / (2 + 1 + 2 + 7 + 2 + 3 + 5 + 6).

It is not an unprimeable number, because it can be changed into a prime (21272351) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 379836 + ... + 379891.

Almost surely, 2^21272356 is an apocalyptic number.

It is an amenable number.

21272356 is a primitive abundant number, since it is smaller than the sum of its proper divisors, none of which is abundant.

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

21272356 is a wasteful number, since it uses less digits than its factorization.

21272356 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 759738 (or 759736 counting only the distinct ones).

The product of its digits is 5040, while the sum is 28.

The square root of 21272356 is about 4612.1964398755. The cubic root of 21272356 is about 277.0800118144.

Adding to 21272356 its reverse (65327212), we get a palindrome (86599568).

The spelling of 21272356 in words is "twenty-one million, two hundred seventy-two thousand, three hundred fifty-six".