21282072 has 48 divisors (see below), whose sum is σ = 61895160. Its totient is φ = 6080256.

The previous prime is 21282059. The next prime is 21282073. The reversal of 21282072 is 27028212.

It is a happy number.

It is a super-2 number, since 2×21282072² = 905853177226368, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21282073) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 7873 + ... + 10224.

Almost surely, 2^21282072 is an apocalyptic number.

It is an amenable number.

21282072 is an abundant number, since it is smaller than the sum of its proper divisors (40613088).

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

21282072 is a wasteful number, since it uses less digits than its factorization.

21282072 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 18120 (or 18109 counting only the distinct ones).

The product of its (nonzero) digits is 896, while the sum is 24.

The square root of 21282072 is about 4613.2496138839. The cubic root of 21282072 is about 277.1221901801.

The spelling of 21282072 in words is "twenty-one million, two hundred eighty-two thousand, seventy-two".