19013021221 has 8 divisors (see below), whose sum is σ = 20140999704. Its totient is φ = 17886105600.

The previous prime is 19013021219. The next prime is 19013021227. The reversal of 19013021221 is 12212031091.

It can be written as a sum of positive squares in 4 ways, for example, as 34928100 + 18978093121 = 5910^2 + 137761^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 19013021221 - 2¹ = 19013021219 is a prime.

It is a super-2 number, since 2×19013021221² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 19013021192 and 19013021201.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (19013021227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 228730 + ... + 300571.

It is an arithmetic number, because the mean of its divisors is an integer number (2517624963).

Almost surely, 2^19013021221 is an apocalyptic number.

It is an amenable number.

19013021221 is a deficient number, since it is larger than the sum of its proper divisors (1127978483).

19013021221 is a wasteful number, since it uses less digits than its factorization.

19013021221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 531431.

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

The spelling of 19013021221 in words is "nineteen billion, thirteen million, twenty-one thousand, two hundred twenty-one".