19494017531209 has 9 divisors (see below), whose sum is σ = 21108968710119. Its totient is φ = 17994424738680.

The previous prime is 19494017531201. The next prime is 19494017531227. The reversal of 19494017531209 is 90213571049491.

It is a happy number.

The square root of 19494017531209 is 4415203.

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., 2883730404025 + 16610287127184 = 1698155^2 + 4075572^2 .

It is not a de Polignac number, because 19494017531209 - 2³ = 19494017531201 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 19494017531209.

It is not an unprimeable number, because it can be changed into a prime (19494017531201) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 57227824 + ... + 57567454.

It is an arithmetic number, because the mean of its divisors is an integer number (2345440967791).

Almost surely, 2^{19494017531209} is an apocalyptic number.

19494017531209 is the 4415203-rd square number.

19494017531209 is the 2207602-nd centered octagonal number.

It is an amenable number.

19494017531209 is a deficient number, since it is larger than the sum of its proper divisors (1614951178910).

19494017531209 is an frugal number, since it uses more digits than its factorization.

19494017531209 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 679288 (or 339644 counting only the distinct ones).

The product of its (nonzero) digits is 2449440, while the sum is 55.

The spelling of 19494017531209 in words is "nineteen trillion, four hundred ninety-four billion, seventeen million, five hundred thirty-one thousand, two hundred nine".