21554172271 has 2 divisors, whose sum is σ = 21554172272. Its totient is φ = 21554172270.

The previous prime is 21554172259. The next prime is 21554172281. The reversal of 21554172271 is 17227145512.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21554172271 - 2⁵ = 21554172239 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21554172271.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21554172281) 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 as a sum of consecutive naturals, namely, 10777086135 + 10777086136.

It is an arithmetic number, because the mean of its divisors is an integer number (10777086136).

Almost surely, 2^21554172271 is an apocalyptic number.

21554172271 is a deficient number, since it is larger than the sum of its proper divisors (1).

21554172271 is an equidigital number, since it uses as much as digits as its factorization.

21554172271 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 39200, while the sum is 37.

The spelling of 21554172271 in words is "twenty-one billion, five hundred fifty-four million, one hundred seventy-two thousand, two hundred seventy-one".