21323530 has 32 divisors (see below), whose sum is σ = 40569984. Its totient is φ = 8053056.

The previous prime is 21323527. The next prime is 21323531. The reversal of 21323530 is 3532312.

It is a junction number, because it is equal to n+sod(n) for n = 21323498 and 21323507.

It is not an unprimeable number, because it can be changed into a prime (21323531) 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, 18532 + ... + 19648.

It is an arithmetic number, because the mean of its divisors is an integer number (1267812).

Almost surely, 2^21323530 is an apocalyptic number.

21323530 is a deficient number, since it is larger than the sum of its proper divisors (19246454).

21323530 is a wasteful number, since it uses less digits than its factorization.

21323530 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1230.

The product of its (nonzero) digits is 540, while the sum is 19.

The square root of 21323530 is about 4617.7407896070. The cubic root of 21323530 is about 277.3020204081.

Adding to 21323530 its reverse (3532312), we get a palindrome (24855842).

The spelling of 21323530 in words is "twenty-one million, three hundred twenty-three thousand, five hundred thirty".