21551743133 has 4 divisors (see below), whose sum is σ = 21552721788. Its totient is φ = 21550764480.

The previous prime is 21551743127. The next prime is 21551743141. The reversal of 21551743133 is 33134715512.

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 10338415684 + 11213327449 = 101678^2 + 105893^2 .

It is a cyclic number.

It is not a de Polignac number, because 21551743133 - 2²⁸ = 21283307677 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21551743093 and 21551743102.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21551743123) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 455516 + ... + 500597.

It is an arithmetic number, because the mean of its divisors is an integer number (5388180447).

Almost surely, 2^21551743133 is an apocalyptic number.

It is an amenable number.

21551743133 is a deficient number, since it is larger than the sum of its proper divisors (978655).

21551743133 is an equidigital number, since it uses as much as digits as its factorization.

21551743133 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 978654.

The product of its digits is 37800, while the sum is 35.

The spelling of 21551743133 in words is "twenty-one billion, five hundred fifty-one million, seven hundred forty-three thousand, one hundred thirty-three".