21129282 has 16 divisors (see below), whose sum is σ = 46954080. Its totient is φ = 7043076.

The previous prime is 21129263. The next prime is 21129287. The reversal of 21129282 is 28292112.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is not an unprimeable number, because it can be changed into a prime (21129287) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 195588 + ... + 195695.

It is an arithmetic number, because the mean of its divisors is an integer number (2934630).

Almost surely, 2^21129282 is an apocalyptic number.

21129282 is an abundant number, since it is smaller than the sum of its proper divisors (25824798).

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

21129282 is a wasteful number, since it uses less digits than its factorization.

21129282 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 391294 (or 391288 counting only the distinct ones).

The product of its digits is 1152, while the sum is 27.

The square root of 21129282 is about 4596.6598743000. The cubic root of 21129282 is about 276.4574173028.

The spelling of 21129282 in words is "twenty-one million, one hundred twenty-nine thousand, two hundred eighty-two".