21240343233 has 16 divisors (see below), whose sum is σ = 31491303360. Its totient is φ = 14149371168.

The previous prime is 21240343217. The next prime is 21240343261. The reversal of 21240343233 is 33234304212.

21240343233 is a `hidden beast` number, since 21 + 2 + 403 + 4 + 3 + 233 = 666.

It is not a de Polignac number, because 21240343233 - 2⁴ = 21240343217 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a Curzon number.

It is a junction number, because it is equal to n+sod(n) for n = 21240343197 and 21240343206.

It is not an unprimeable number, because it can be changed into a prime (21240343933) 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, 265660 + ... + 336237.

It is an arithmetic number, because the mean of its divisors is an integer number (1968206460).

Almost surely, 2^21240343233 is an apocalyptic number.

It is an amenable number.

21240343233 is a deficient number, since it is larger than the sum of its proper divisors (10250960127).

21240343233 is a wasteful number, since it uses less digits than its factorization.

21240343233 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 603213 (or 603207 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 27.

Adding to 21240343233 its reverse (33234304212), we get a palindrome (54474647445).

The spelling of 21240343233 in words is "twenty-one billion, two hundred forty million, three hundred forty-three thousand, two hundred thirty-three".