21281832 has 192 divisors, whose sum is σ = 71150400. Its totient is φ = 5840640.

The previous prime is 21281797. The next prime is 21281891. The reversal of 21281832 is 23818212.

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

It is a nude number because it is divisible by every one of its digits.

It is a junction number, because it is equal to n+sod(n) for n = 21281796 and 21281805.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 401518 + ... + 401570.

It is an arithmetic number, because the mean of its divisors is an integer number (370575).

Almost surely, 2^21281832 is an apocalyptic number.

21281832 is a gapful number since it is divisible by the number (22) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21281832, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (35575200).

21281832 is an abundant number, since it is smaller than the sum of its proper divisors (49868568).

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

21281832 is a wasteful number, since it uses less digits than its factorization.

21281832 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 105 (or 82 counting only the distinct ones).

The product of its digits is 1536, while the sum is 27.

The square root of 21281832 is about 4613.2236017778. The cubic root of 21281832 is about 277.1211484648.

The spelling of 21281832 in words is "twenty-one million, two hundred eighty-one thousand, eight hundred thirty-two".