21240232043 has 4 divisors (see below), whose sum is σ = 21240620328. Its totient is φ = 21239843760.

The previous prime is 21240232019. The next prime is 21240232049. The reversal of 21240232043 is 34023204212.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21240232043 - 2²⁴ = 21223454827 is a prime.

It is a super-2 number, since 2×21240232043² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21240232049) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 95321 + ... + 227082.

It is an arithmetic number, because the mean of its divisors is an integer number (5310155082).

Almost surely, 2^21240232043 is an apocalyptic number.

21240232043 is a deficient number, since it is larger than the sum of its proper divisors (388285).

21240232043 is an equidigital number, since it uses as much as digits as its factorization.

21240232043 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 388284.

The product of its (nonzero) digits is 2304, while the sum is 23.

Adding to 21240232043 its reverse (34023204212), we get a palindrome (55263436255).

The spelling of 21240232043 in words is "twenty-one billion, two hundred forty million, two hundred thirty-two thousand, forty-three".