21227737243 has 2 divisors, whose sum is σ = 21227737244. Its totient is φ = 21227737242.

The previous prime is 21227737241. The next prime is 21227737291. The reversal of 21227737243 is 34273772212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21227737243 - 2¹ = 21227737241 is a prime.

Together with 21227737241, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 21227737196 and 21227737205.

It is not a weakly prime, because it can be changed into another prime (21227737241) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10613868621 + 10613868622.

It is an arithmetic number, because the mean of its divisors is an integer number (10613868622).

Almost surely, 2^21227737243 is an apocalyptic number.

21227737243 is a deficient number, since it is larger than the sum of its proper divisors (1).

21227737243 is an equidigital number, since it uses as much as digits as its factorization.

21227737243 is an evil number, because the sum of its binary digits is even.

The product of its digits is 197568, while the sum is 40.

The spelling of 21227737243 in words is "twenty-one billion, two hundred twenty-seven million, seven hundred thirty-seven thousand, two hundred forty-three".