21042332 has 24 divisors (see below), whose sum is σ = 38596992. Its totient is φ = 10018800.

The previous prime is 21042319. The next prime is 21042347. The reversal of 21042332 is 23324012.

It is a plaindrome in base 13.

It is a self number, because there is not a number n which added to its sum of digits gives 21042332.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30107 + ... + 30797.

It is an arithmetic number, because the mean of its divisors is an integer number (1608208).

Almost surely, 2^21042332 is an apocalyptic number.

It is an amenable number.

21042332 is a deficient number, since it is larger than the sum of its proper divisors (17554660).

21042332 is a wasteful number, since it uses less digits than its factorization.

21042332 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1049 (or 1047 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 17.

The square root of 21042332 is about 4587.1921695085. The cubic root of 21042332 is about 276.0776754000.

Adding to 21042332 its reverse (23324012), we get a palindrome (44366344).

The spelling of 21042332 in words is "twenty-one million, forty-two thousand, three hundred thirty-two".