21120732 has 36 divisors (see below), whose sum is σ = 56530656. Its totient is φ = 6625920.

The previous prime is 21120731. The next prime is 21120733. The reversal of 21120732 is 23702112.

It is an interprime number because it is at equal distance from previous prime (21120731) and next prime (21120733).

It is a tau number, because it is divible by the number of its divisors (36).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21120731) by changing a digit.

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 11 ways as a sum of consecutive naturals, for example, 16644 + ... + 17867.

It is an arithmetic number, because the mean of its divisors is an integer number (1570296).

Almost surely, 2^21120732 is an apocalyptic number.

It is an amenable number.

21120732 is an abundant number, since it is smaller than the sum of its proper divisors (35409924).

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

21120732 is a wasteful number, since it uses less digits than its factorization.

21120732 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 34538 (or 34533 counting only the distinct ones).

The product of its (nonzero) digits is 168, while the sum is 18.

The square root of 21120732 is about 4595.7297570680. The cubic root of 21120732 is about 276.4201226167.

Adding to 21120732 its reverse (23702112), we get a palindrome (44822844).

The spelling of 21120732 in words is "twenty-one million, one hundred twenty thousand, seven hundred thirty-two".