21251022533 has 8 divisors (see below), whose sum is σ = 24231935448. Its totient is φ = 18462426624.

The previous prime is 21251022503. The next prime is 21251022539. The reversal of 21251022533 is 33522015212.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 3112858849 + 18138163684 = 55793^2 + 134678^2 .

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 21251022533 - 2⁶ = 21251022469 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21251022539) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 48079016 + ... + 48079457.

It is an arithmetic number, because the mean of its divisors is an integer number (3028991931).

Almost surely, 2^21251022533 is an apocalyptic number.

It is an amenable number.

21251022533 is a deficient number, since it is larger than the sum of its proper divisors (2980912915).

21251022533 is a wasteful number, since it uses less digits than its factorization.

21251022533 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 96158503.

The product of its (nonzero) digits is 3600, while the sum is 26.

Adding to 21251022533 its reverse (33522015212), we get a palindrome (54773037745).

The spelling of 21251022533 in words is "twenty-one billion, two hundred fifty-one million, twenty-two thousand, five hundred thirty-three".