21293532 has 72 divisors (see below), whose sum is σ = 58522464. Its totient is φ = 6489216.

The previous prime is 21293521. The next prime is 21293563. The reversal of 21293532 is 23539212.

21293532 is a `hidden beast` number, since 2 + 129 + 3 + 532 = 666.

It is a super-3 number, since 3×21293532³ (a number of 23 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 21293496 and 21293505.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 80833 + ... + 81095.

It is an arithmetic number, because the mean of its divisors is an integer number (812812).

Almost surely, 2^21293532 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21293532, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29261232).

21293532 is an abundant number, since it is smaller than the sum of its proper divisors (37228932).

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

21293532 is a wasteful number, since it uses less digits than its factorization.

21293532 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 459 (or 454 counting only the distinct ones).

The product of its digits is 3240, while the sum is 27.

The square root of 21293532 is about 4614.4915212838. The cubic root of 21293532 is about 277.1719229697.

The spelling of 21293532 in words is "twenty-one million, two hundred ninety-three thousand, five hundred thirty-two".