19845456361 has 4 divisors (see below), whose sum is σ = 20329491924. Its totient is φ = 19361420800.

The previous prime is 19845456343. The next prime is 19845456377. The reversal of 19845456361 is 16365454891.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 16365454891 = 23 ⋅711541517.

It can be written as a sum of positive squares in 2 ways, for example, as 7361640000 + 12483816361 = 85800^2 + 111731^2 .

It is a cyclic number.

It is not a de Polignac number, because 19845456361 - 2⁹ = 19845455849 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 19845456299 and 19845456308.

It is not an unprimeable number, because it can be changed into a prime (19845426361) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 242017720 + ... + 242017801.

It is an arithmetic number, because the mean of its divisors is an integer number (5082372981).

Almost surely, 2^19845456361 is an apocalyptic number.

It is an amenable number.

19845456361 is a deficient number, since it is larger than the sum of its proper divisors (484035563).

19845456361 is an equidigital number, since it uses as much as digits as its factorization.

19845456361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 484035562.

The product of its digits is 3110400, while the sum is 52.

The spelling of 19845456361 in words is "nineteen billion, eight hundred forty-five million, four hundred fifty-six thousand, three hundred sixty-one".