21282772 has 24 divisors (see below), whose sum is σ = 43606080. Its totient is φ = 8898240.

The previous prime is 21282769. The next prime is 21282791. The reversal of 21282772 is 27728212.

21282772 is a modest number, since divided by 2772 gives 2128 as remainder.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8122 + ... + 10417.

It is an arithmetic number, because the mean of its divisors is an integer number (1816920).

Almost surely, 2^21282772 is an apocalyptic number.

It is an amenable number.

21282772 is an abundant number, since it is smaller than the sum of its proper divisors (22323308).

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

21282772 is a wasteful number, since it uses less digits than its factorization.

21282772 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18591 (or 18589 counting only the distinct ones).

The product of its digits is 6272, while the sum is 31.

The square root of 21282772 is about 4613.3254816889. The cubic root of 21282772 is about 277.1252284714.

It can be divided in two parts, 2128 and 2772, that added together give a square (4900 = 70²).

The spelling of 21282772 in words is "twenty-one million, two hundred eighty-two thousand, seven hundred seventy-two".