21554043211 has 16 divisors (see below), whose sum is σ = 22302314496. Its totient is φ = 20817160000.

The previous prime is 21554043191. The next prime is 21554043223. The reversal of 21554043211 is 11234045512.

It is a cyclic number.

It is not a de Polignac number, because 21554043211 - 2²⁹ = 21017172299 is a prime.

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 21554043211.

It is not an unprimeable number, because it can be changed into a prime (21554043241) 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, 2310246 + ... + 2319556.

It is an arithmetic number, because the mean of its divisors is an integer number (1393894656).

Almost surely, 2^21554043211 is an apocalyptic number.

21554043211 is a deficient number, since it is larger than the sum of its proper divisors (748271285).

21554043211 is a wasteful number, since it uses less digits than its factorization.

21554043211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9914.

The product of its (nonzero) digits is 4800, while the sum is 28.

Adding to 21554043211 its reverse (11234045512), we get a palindrome (32788088723).

The spelling of 21554043211 in words is "twenty-one billion, five hundred fifty-four million, forty-three thousand, two hundred eleven".