21221211043 has 2 divisors, whose sum is σ = 21221211044. Its totient is φ = 21221211042.

The previous prime is 21221211019. The next prime is 21221211059. The reversal of 21221211043 is 34011212212.

It is a strong prime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21221211043 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 21221211043.

It is not a weakly prime, because it can be changed into another prime (21221211743) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610605521 + 10610605522.

It is an arithmetic number, because the mean of its divisors is an integer number (10610605522).

Almost surely, 2^21221211043 is an apocalyptic number.

21221211043 is a deficient number, since it is larger than the sum of its proper divisors (1).

21221211043 is an equidigital number, since it uses as much as digits as its factorization.

21221211043 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 192, while the sum is 19.

Adding to 21221211043 its reverse (34011212212), we get a palindrome (55232423255).

The spelling of 21221211043 in words is "twenty-one billion, two hundred twenty-one million, two hundred eleven thousand, forty-three".