21232305 has 24 divisors (see below), whose sum is σ = 37003200. Its totient is φ = 11262240.

The previous prime is 21232259. The next prime is 21232307. The reversal of 21232305 is 50323212.

It is not a de Polignac number, because 21232305 - 2⁸ = 21232049 is a prime.

It is a super-2 number, since 2×21232305² = 901621551226050, which contains 22 as substring.

It is an alternating number because its digits alternate between even and odd.

It is not an unprimeable number, because it can be changed into a prime (21232307) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 7770 + ... + 10140.

It is an arithmetic number, because the mean of its divisors is an integer number (1541800).

Almost surely, 2^21232305 is an apocalyptic number.

It is an amenable number.

21232305 is a deficient number, since it is larger than the sum of its proper divisors (15770895).

21232305 is a wasteful number, since it uses less digits than its factorization.

21232305 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2581 (or 2578 counting only the distinct ones).

The product of its (nonzero) digits is 360, while the sum is 18.

The square root of 21232305 is about 4607.8525367030. The cubic root of 21232305 is about 276.9060097209.

Adding to 21232305 its reverse (50323212), we get a palindrome (71555517).

The spelling of 21232305 in words is "twenty-one million, two hundred thirty-two thousand, three hundred five".