21251235234353 has 4 divisors (see below), whose sum is σ = 21361345261668. Its totient is φ = 21141125207040.

The previous prime is 21251235234343. The next prime is 21251235234367. The reversal of 21251235234353 is 35343253215212.

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

It can be written as a sum of positive squares in 2 ways, for example, as 7738678295104 + 13512556939249 = 2781848^2 + 3675943^2 .

It is a cyclic number.

It is not a de Polignac number, because 21251235234353 - 2⁶ = 21251235234289 is a prime.

It is a super-2 number, since 2×21251235234353² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21251235234353.

It is not an unprimeable number, because it can be changed into a prime (21251235234343) 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, 55055013368 + ... + 55055013753.

It is an arithmetic number, because the mean of its divisors is an integer number (5340336315417).

Almost surely, 2^{21251235234353} is an apocalyptic number.

It is an amenable number.

21251235234353 is a deficient number, since it is larger than the sum of its proper divisors (110110027315).

21251235234353 is a wasteful number, since it uses less digits than its factorization.

21251235234353 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 110110027314.

The product of its digits is 648000, while the sum is 41.

Adding to 21251235234353 its reverse (35343253215212), we get a palindrome (56594488449565).

The spelling of 21251235234353 in words is "twenty-one trillion, two hundred fifty-one billion, two hundred thirty-five million, two hundred thirty-four thousand, three hundred fifty-three".