21234043345 has 8 divisors (see below), whose sum is σ = 25482401064. Its totient is φ = 16986201984.

The previous prime is 21234043283. The next prime is 21234043357. The reversal of 21234043345 is 54334043212.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 16384 + 21234026961 = 128^2 + 145719^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21234043345 - 2⁹ = 21234042833 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 31974 + ... + 208543.

It is an arithmetic number, because the mean of its divisors is an integer number (3185300133).

Almost surely, 2^21234043345 is an apocalyptic number.

It is an amenable number.

21234043345 is a deficient number, since it is larger than the sum of its proper divisors (4248357719).

21234043345 is a wasteful number, since it uses less digits than its factorization.

21234043345 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 258179.

The product of its (nonzero) digits is 34560, while the sum is 31.

Adding to 21234043345 its reverse (54334043212), we get a palindrome (75568086557).

The spelling of 21234043345 in words is "twenty-one billion, two hundred thirty-four million, forty-three thousand, three hundred forty-five".