15561840445 has 8 divisors (see below), whose sum is σ = 18725094144. Its totient is φ = 12415548624.

The previous prime is 15561840433. The next prime is 15561840449. The reversal of 15561840445 is 54404816551.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 15561840445 - 2⁷ = 15561840317 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15561840449) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 4238449 + ... + 4242118.

It is an arithmetic number, because the mean of its divisors is an integer number (2340636768).

Almost surely, 2^15561840445 is an apocalyptic number.

It is an amenable number.

15561840445 is a deficient number, since it is larger than the sum of its proper divisors (3163253699).

15561840445 is an equidigital number, since it uses as much as digits as its factorization.

15561840445 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8480939.

The product of its (nonzero) digits is 384000, while the sum is 43.

The spelling of 15561840445 in words is "fifteen billion, five hundred sixty-one million, eight hundred forty thousand, four hundred forty-five".