21743271891 has 12 divisors (see below), whose sum is σ = 34262125560. Its totient is φ = 13177740480.

The previous prime is 21743271857. The next prime is 21743271917. The reversal of 21743271891 is 19817234712.

It is not a de Polignac number, because 21743271891 - 2¹⁷ = 21743140819 is a prime.

It is not an unprimeable number, because it can be changed into a prime (21743271811) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 109814406 + ... + 109814603.

It is an arithmetic number, because the mean of its divisors is an integer number (2855177130).

Almost surely, 2^21743271891 is an apocalyptic number.

21743271891 is a deficient number, since it is larger than the sum of its proper divisors (12518853669).

21743271891 is a wasteful number, since it uses less digits than its factorization.

21743271891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 219629026 (or 219629023 counting only the distinct ones).

The product of its digits is 169344, while the sum is 45.

Adding to 21743271891 its sum of digits (45), we get a 4-th power (21743271936 = 384⁴).

The spelling of 21743271891 in words is "twenty-one billion, seven hundred forty-three million, two hundred seventy-one thousand, eight hundred ninety-one".