21021031219 has 2 divisors, whose sum is σ = 21021031220. Its totient is φ = 21021031218.

The previous prime is 21021031193. The next prime is 21021031259. The reversal of 21021031219 is 91213012012.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 21021031219 - 2⁷ = 21021031091 is a prime.

It is a super-2 number, since 2×21021031219² (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 21021031219.

It is not a weakly prime, because it can be changed into another prime (21021031259) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10510515609 + 10510515610.

It is an arithmetic number, because the mean of its divisors is an integer number (10510515610).

Almost surely, 2^21021031219 is an apocalyptic number.

21021031219 is a deficient number, since it is larger than the sum of its proper divisors (1).

21021031219 is an equidigital number, since it uses as much as digits as its factorization.

21021031219 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 216, while the sum is 22.

The spelling of 21021031219 in words is "twenty-one billion, twenty-one million, thirty-one thousand, two hundred nineteen".