19794520249 has 27 divisors (see below), whose sum is σ = 23373973071. Its totient is φ = 16714328400.

The previous prime is 19794520247. The next prime is 19794520259. The reversal of 19794520249 is 94202549791.

The square root of 19794520249 is 140693.

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., 19018340649 + 776179600 = 137907^2 + 27860^2 .

It is not a de Polignac number, because 19794520249 - 2¹ = 19794520247 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 19794520196 and 19794520205.

It is not an unprimeable number, because it can be changed into a prime (19794520247) by changing a digit.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 99469852 + ... + 99470050.

Almost surely, 2^19794520249 is an apocalyptic number.

19794520249 is the 140693-rd square number.

19794520249 is the 70347-th centered octagonal number.

It is an amenable number.

19794520249 is a deficient number, since it is larger than the sum of its proper divisors (3579452822).

19794520249 is an frugal number, since it uses more digits than its factorization.

19794520249 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 614 (or 307 counting only the distinct ones).

The product of its (nonzero) digits is 1632960, while the sum is 52.

The spelling of 19794520249 in words is "nineteen billion, seven hundred ninety-four million, five hundred twenty thousand, two hundred forty-nine".