21551433143 has 16 divisors (see below), whose sum is σ = 22587102720. Its totient is φ = 20535800544.

The previous prime is 21551433139. The next prime is 21551433149. The reversal of 21551433143 is 34133415512.

It is a cyclic number.

It is not a de Polignac number, because 21551433143 - 2² = 21551433139 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21551433149) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2554430 + ... + 2562852.

It is an arithmetic number, because the mean of its divisors is an integer number (1411693920).

Almost surely, 2^21551433143 is an apocalyptic number.

21551433143 is a deficient number, since it is larger than the sum of its proper divisors (1035669577).

21551433143 is a wasteful number, since it uses less digits than its factorization.

21551433143 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9598.

The product of its digits is 21600, while the sum is 32.

Adding to 21551433143 its reverse (34133415512), we get a palindrome (55684848655).

The spelling of 21551433143 in words is "twenty-one billion, five hundred fifty-one million, four hundred thirty-three thousand, one hundred forty-three".