21150432 has 144 divisors (see below), whose sum is σ = 65415168. Its totient is φ = 6462720.

The previous prime is 21150407. The next prime is 21150443. The reversal of 21150432 is 23405112.

It is a tau number, because it is divible by the number of its divisors (144).

It is a hoax number, since the sum of its digits (18) coincides with the sum of the digits of its distinct prime factors.

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

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 205293 + ... + 205395.

It is an arithmetic number, because the mean of its divisors is an integer number (454272).

Almost surely, 2^21150432 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 21150432, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32707584).

21150432 is an abundant number, since it is smaller than the sum of its proper divisors (44264736).

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

21150432 is a wasteful number, since it uses less digits than its factorization.

21150432 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 173 (or 162 counting only the distinct ones).

The product of its (nonzero) digits is 240, while the sum is 18.

The square root of 21150432 is about 4598.9598824082. The cubic root of 21150432 is about 276.5496293733.

Adding to 21150432 its reverse (23405112), we get a palindrome (44555544).

The spelling of 21150432 in words is "twenty-one million, one hundred fifty thousand, four hundred thirty-two".