21233930 has 16 divisors (see below), whose sum is σ = 39254760. Its totient is φ = 8263872.

The previous prime is 21233911. The next prime is 21233939. The reversal of 21233930 is 3933212.

It can be written as a sum of positive squares in 4 ways, for example, as 20894041 + 339889 = 4571^2 + 583^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21233896 and 21233905.

It is not an unprimeable number, because it can be changed into a prime (21233939) 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, 28325 + ... + 29064.

Almost surely, 2^21233930 is an apocalyptic number.

21233930 is a deficient number, since it is larger than the sum of its proper divisors (18020830).

21233930 is a wasteful number, since it uses less digits than its factorization.

21233930 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 57433.

The product of its (nonzero) digits is 972, while the sum is 23.

The square root of 21233930 is about 4608.0288627568. The cubic root of 21233930 is about 276.9130738117.

The spelling of 21233930 in words is "twenty-one million, two hundred thirty-three thousand, nine hundred thirty".