21732030 has 32 divisors (see below), whose sum is σ = 57952800. Its totient is φ = 5795136.

The previous prime is 21732017. The next prime is 21732037. The reversal of 21732030 is 3023712.

It is a super-2 number, since 2×21732030² = 944562255841800, which contains 22 as substring.

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

It is a junction number, because it is equal to n+sod(n) for n = 21731994 and 21732012.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21732037) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 39975 + ... + 40514.

It is an arithmetic number, because the mean of its divisors is an integer number (1811025).

Almost surely, 2^21732030 is an apocalyptic number.

21732030 is an abundant number, since it is smaller than the sum of its proper divisors (36220770).

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

21732030 is a wasteful number, since it uses less digits than its factorization.

21732030 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 80505 (or 80499 counting only the distinct ones).

The product of its (nonzero) digits is 252, while the sum is 18.

The square root of 21732030 is about 4661.7625422151. The cubic root of 21732030 is about 279.0616120146.

Adding to 21732030 its reverse (3023712), we get a palindrome (24755742).

The spelling of 21732030 in words is "twenty-one million, seven hundred thirty-two thousand, thirty".