19713002409 has 27 divisors (see below), whose sum is σ = 30258816133. Its totient is φ = 12364449792.

The previous prime is 19713002381. The next prime is 19713002411. The reversal of 19713002409 is 90420031791.

The square root of 19713002409 is 140403.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in 4 ways, for example, as 10404612009 + 9308390400 = 102003^2 + 96480^2 .

It is not a de Polignac number, because 19713002409 - 2²¹ = 19710905257 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19713002429) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 7159177 + ... + 7161929.

Almost surely, 2^19713002409 is an apocalyptic number.

19713002409 is the 140403-rd square number.

19713002409 is the 70202-nd centered octagonal number.

It is an amenable number.

19713002409 is a deficient number, since it is larger than the sum of its proper divisors (10545813724).

19713002409 is an frugal number, since it uses more digits than its factorization.

19713002409 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5546 (or 2773 counting only the distinct ones).

The product of its (nonzero) digits is 13608, while the sum is 36.

Multiplying 19713002409 by its sum of digits (36), we get a square (709668086724 = 842418²).

The spelling of 19713002409 in words is "nineteen billion, seven hundred thirteen million, two thousand, four hundred nine".