21430332 has 120 divisors (see below), whose sum is σ = 69928320. Its totient is φ = 5559840.

The previous prime is 21430327. The next prime is 21430369. The reversal of 21430332 is 23303412.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 24519 + ... + 25377.

It is an arithmetic number, because the mean of its divisors is an integer number (582736).

Almost surely, 2^21430332 is an apocalyptic number.

21430332 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 21430332, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (34964160).

21430332 is an abundant number, since it is smaller than the sum of its proper divisors (48497988).

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

21430332 is a wasteful number, since it uses less digits than its factorization.

21430332 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 893 (or 882 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 18.

The square root of 21430332 is about 4629.2906584055. The cubic root of 21430332 is about 277.7642187633.

Adding to 21430332 its reverse (23303412), we get a palindrome (44733744).

Subtracting 21430332 from its reverse (23303412), we obtain a triangular number (1873080 = T₁₉₃₅).

The spelling of 21430332 in words is "twenty-one million, four hundred thirty thousand, three hundred thirty-two".