21221211019 has 2 divisors, whose sum is σ = 21221211020. Its totient is φ = 21221211018.

The previous prime is 21221211007. The next prime is 21221211043. The reversal of 21221211019 is 91011212212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21221211019 - 2¹¹ = 21221208971 is a prime.

It is a super-2 number, since 2×21221211019² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21221211059) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610605509 + 10610605510.

It is an arithmetic number, because the mean of its divisors is an integer number (10610605510).

Almost surely, 2^21221211019 is an apocalyptic number.

21221211019 is a deficient number, since it is larger than the sum of its proper divisors (1).

21221211019 is an equidigital number, since it uses as much as digits as its factorization.

21221211019 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 144, while the sum is 22.

The spelling of 21221211019 in words is "twenty-one billion, two hundred twenty-one million, two hundred eleven thousand, nineteen".