21221222819 has 2 divisors, whose sum is σ = 21221222820. Its totient is φ = 21221222818.

The previous prime is 21221222761. The next prime is 21221222833. The reversal of 21221222819 is 91822212212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21221222819 - 2¹² = 21221218723 is a prime.

It is a super-2 number, since 2×21221222819² (a number of 21 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (21221222219) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10610611409 + 10610611410.

It is an arithmetic number, because the mean of its divisors is an integer number (10610611410).

Almost surely, 2^21221222819 is an apocalyptic number.

21221222819 is a deficient number, since it is larger than the sum of its proper divisors (1).

21221222819 is an equidigital number, since it uses as much as digits as its factorization.

21221222819 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4608, while the sum is 32.

The spelling of 21221222819 in words is "twenty-one billion, two hundred twenty-one million, two hundred twenty-two thousand, eight hundred nineteen".