21933020 has 24 divisors (see below), whose sum is σ = 47041344. Its totient is φ = 8586176.

The previous prime is 21933013. The next prime is 21933029. The reversal of 21933020 is 2033912.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is a junction number, because it is equal to n+sod(n) for n = 21932983 and 21933001.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21933029) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10727 + ... + 12606.

It is an arithmetic number, because the mean of its divisors is an integer number (1960056).

Almost surely, 2^21933020 is an apocalyptic number.

21933020 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

21933020 is an abundant number, since it is smaller than the sum of its proper divisors (25108324).

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

21933020 is a wasteful number, since it uses less digits than its factorization.

21933020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 23389 (or 23387 counting only the distinct ones).

The product of its (nonzero) digits is 324, while the sum is 20.

The square root of 21933020 is about 4683.2702249603. The cubic root of 21933020 is about 279.9192794526.

Adding to 21933020 its reverse (2033912), we get a palindrome (23966932).

The spelling of 21933020 in words is "twenty-one million, nine hundred thirty-three thousand, twenty".