21002021219 has 2 divisors, whose sum is σ = 21002021220. Its totient is φ = 21002021218.

The previous prime is 21002021197. The next prime is 21002021269. The reversal of 21002021219 is 91212020012.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21002021219 - 2¹⁶ = 21001955683 is a prime.

It is a super-2 number, since 2×21002021219² (a number of 21 digits) contains 22 as substring.

It is a self number, because there is not a number n which added to its sum of digits gives 21002021219.

It is not a weakly prime, because it can be changed into another prime (21002021269) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10501010609 + 10501010610.

It is an arithmetic number, because the mean of its divisors is an integer number (10501010610).

Almost surely, 2^21002021219 is an apocalyptic number.

21002021219 is a deficient number, since it is larger than the sum of its proper divisors (1).

21002021219 is an equidigital number, since it uses as much as digits as its factorization.

21002021219 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 20.

The spelling of 21002021219 in words is "twenty-one billion, two million, twenty-one thousand, two hundred nineteen".