21621352233 has 32 divisors (see below), whose sum is σ = 34602422400. Its totient is φ = 11863673856.

The previous prime is 21621352231. The next prime is 21621352253. The reversal of 21621352233 is 33225312612.

It is not a de Polignac number, because 21621352233 - 2¹ = 21621352231 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21621352233.

It is not an unprimeable number, because it can be changed into a prime (21621352231) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 845598 + ... + 870791.

It is an arithmetic number, because the mean of its divisors is an integer number (1081325700).

Almost surely, 2^21621352233 is an apocalyptic number.

It is an amenable number.

21621352233 is a deficient number, since it is larger than the sum of its proper divisors (12981070167).

21621352233 is a wasteful number, since it uses less digits than its factorization.

21621352233 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1716441.

The product of its digits is 12960, while the sum is 30.

Adding to 21621352233 its reverse (33225312612), we get a palindrome (54846664845).

The spelling of 21621352233 in words is "twenty-one billion, six hundred twenty-one million, three hundred fifty-two thousand, two hundred thirty-three".