21243333427 has 2 divisors, whose sum is σ = 21243333428. Its totient is φ = 21243333426.

The previous prime is 21243333317. The next prime is 21243333487. The reversal of 21243333427 is 72433334212.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21243333427 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21243333392 and 21243333401.

It is not a weakly prime, because it can be changed into another prime (21243333487) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10621666713 + 10621666714.

It is an arithmetic number, because the mean of its divisors is an integer number (10621666714).

Almost surely, 2^21243333427 is an apocalyptic number.

21243333427 is a deficient number, since it is larger than the sum of its proper divisors (1).

21243333427 is an equidigital number, since it uses as much as digits as its factorization.

21243333427 is an evil number, because the sum of its binary digits is even.

The product of its digits is 72576, while the sum is 34.

Adding to 21243333427 its reverse (72433334212), we get a palindrome (93676667639).

The spelling of 21243333427 in words is "twenty-one billion, two hundred forty-three million, three hundred thirty-three thousand, four hundred twenty-seven".