21743271937 has 4 divisors (see below), whose sum is σ = 21743915076. Its totient is φ = 21742628800.

The previous prime is 21743271923. The next prime is 21743271967. The reversal of 21743271937 is 73917234712.

It is a Cunningham number, because it is equal to 384⁴+1.

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 4022603776 + 17720668161 = 63424^2 + 133119^2 .

It is a cyclic number.

It is not a de Polignac number, because 21743271937 - 2¹⁵ = 21743239169 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21743271917) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 267868 + ... + 339469.

It is an arithmetic number, because the mean of its divisors is an integer number (5435978769).

It is a Proth number, since it is equal to 81 ⋅ 2²⁸ + 1 and 81 < 2²⁸.

Almost surely, 2^21743271937 is an apocalyptic number.

It is an amenable number.

21743271937 is a deficient number, since it is larger than the sum of its proper divisors (643139).

21743271937 is an equidigital number, since it uses as much as digits as its factorization.

21743271937 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 643138.

The product of its digits is 444528, while the sum is 46.

The spelling of 21743271937 in words is "twenty-one billion, seven hundred forty-three million, two hundred seventy-one thousand, nine hundred thirty-seven".