19305399351681 has 63 divisors (see below), whose sum is σ = 29090189129497. Its totient is φ = 12805967496960.

The previous prime is 19305399351671. The next prime is 19305399351751. The reversal of 19305399351681 is 18615399350391.

The square root of 19305399351681 is 4393791.

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

19305399351681 is a `hidden beast` number, since 1 + 9 + 3 + 0 + 5 + 39 + 9 + 3 + 516 + 81 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 1452374471025 + 17853024880656 = 1205145^2 + 4225284^2 .

It is not a de Polignac number, because 19305399351681 - 2⁵ = 19305399351649 is a prime.

It is a super-2 number, since 2×19305399351681² (a number of 27 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (19305399351611) by changing a digit.

It is a polite number, since it can be written in 62 ways as a sum of consecutive naturals, for example, 41877221791 + ... + 41877222251.

Almost surely, 2^{19305399351681} is an apocalyptic number.

19305399351681 is the 4393791-st square number.

19305399351681 is the 2196896-th centered octagonal number.

It is an amenable number.

19305399351681 is a deficient number, since it is larger than the sum of its proper divisors (9784789777816).

19305399351681 is an frugal number, since it uses more digits than its factorization.

19305399351681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1646 (or 817 counting only the distinct ones).

The product of its (nonzero) digits is 23619600, while the sum is 63.

The spelling of 19305399351681 in words is "nineteen trillion, three hundred five billion, three hundred ninety-nine million, three hundred fifty-one thousand, six hundred eighty-one".