15605840991 has 8 divisors (see below), whose sum is σ = 22408387120. Its totient is φ = 9603594432.

The previous prime is 15605840923. The next prime is 15605840993. The reversal of 15605840991 is 19904850651.

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

It is not a de Polignac number, because 15605840991 - 2¹⁸ = 15605578847 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 15605840991.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15605840993) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 200074846 + ... + 200074923.

It is an arithmetic number, because the mean of its divisors is an integer number (2801048390).

Almost surely, 2^15605840991 is an apocalyptic number.

15605840991 is a deficient number, since it is larger than the sum of its proper divisors (6802546129).

15605840991 is a wasteful number, since it uses less digits than its factorization.

15605840991 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 400149785.

The product of its (nonzero) digits is 388800, while the sum is 48.

The spelling of 15605840991 in words is "fifteen billion, six hundred five million, eight hundred forty thousand, nine hundred ninety-one".