19709071321 has 27 divisors (see below), whose sum is σ = 21060118911. Its totient is φ = 18443745264.

The previous prime is 19709071303. The next prime is 19709071399. The reversal of 19709071321 is 12317090791.

The square root of 19709071321 is 140389.

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

It can be written as a sum of positive squares in only one way, i.e., 10334958921 + 9374112400 = 101661^2 + 96820^2 .

It is not a de Polignac number, because 19709071321 - 2¹⁷ = 19708940249 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19709071721) 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 26 ways as a sum of consecutive naturals, for example, 191350156 + ... + 191350258.

Almost surely, 2^19709071321 is an apocalyptic number.

19709071321 is the 140389-th square number.

19709071321 is the 70195-th centered octagonal number.

It is an amenable number.

19709071321 is a deficient number, since it is larger than the sum of its proper divisors (1351047590).

19709071321 is an frugal number, since it uses more digits than its factorization.

19709071321 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 358 (or 179 counting only the distinct ones).

The product of its (nonzero) digits is 23814, while the sum is 40.

The spelling of 19709071321 in words is "nineteen billion, seven hundred nine million, seventy-one thousand, three hundred twenty-one".