21211221019 has 2 divisors, whose sum is σ = 21211221020. Its totient is φ = 21211221018.

The previous prime is 21211220993. The next prime is 21211221061. The reversal of 21211221019 is 91012211212.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21211221019 - 2²³ = 21202832411 is a prime.

It is a super-2 number, since 2×21211221019² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21211221089) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10605610509 + 10605610510.

It is an arithmetic number, because the mean of its divisors is an integer number (10605610510).

Almost surely, 2^21211221019 is an apocalyptic number.

21211221019 is a deficient number, since it is larger than the sum of its proper divisors (1).

21211221019 is an equidigital number, since it uses as much as digits as its factorization.

21211221019 is an odious number, because the sum of its binary digits is odd.

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

The spelling of 21211221019 in words is "twenty-one billion, two hundred eleven million, two hundred twenty-one thousand, nineteen".