21231121027 has 2 divisors, whose sum is σ = 21231121028. Its totient is φ = 21231121026.

The previous prime is 21231120971. The next prime is 21231121081. The reversal of 21231121027 is 72012113212.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21231121027 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21231120989 and 21231121007.

It is not a weakly prime, because it can be changed into another prime (21231121127) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10615560513 + 10615560514.

It is an arithmetic number, because the mean of its divisors is an integer number (10615560514).

Almost surely, 2^21231121027 is an apocalyptic number.

21231121027 is a deficient number, since it is larger than the sum of its proper divisors (1).

21231121027 is an equidigital number, since it uses as much as digits as its factorization.

21231121027 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 336, while the sum is 22.

Adding to 21231121027 its reverse (72012113212), we get a palindrome (93243234239).

The spelling of 21231121027 in words is "twenty-one billion, two hundred thirty-one million, one hundred twenty-one thousand, twenty-seven".