21772847171 has 4 divisors (see below), whose sum is σ = 21976331832. Its totient is φ = 21569362512.

The previous prime is 21772847147. The next prime is 21772847183. The reversal of 21772847171 is 17174827712.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 21772847171 - 2¹⁸ = 21772585027 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21772847111) 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, 101742170 + ... + 101742383.

It is an arithmetic number, because the mean of its divisors is an integer number (5494082958).

Almost surely, 2^21772847171 is an apocalyptic number.

21772847171 is a deficient number, since it is larger than the sum of its proper divisors (203484661).

21772847171 is a wasteful number, since it uses less digits than its factorization.

21772847171 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 203484660.

The product of its digits is 307328, while the sum is 47.

The spelling of 21772847171 in words is "twenty-one billion, seven hundred seventy-two million, eight hundred forty-seven thousand, one hundred seventy-one".