15561941587 has 4 divisors (see below), whose sum is σ = 15563856616. Its totient is φ = 15560026560.

The previous prime is 15561941573. The next prime is 15561941597. The reversal of 15561941587 is 78514916551.

15561941587 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 15561941587 - 2³¹ = 13414457939 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15561941537) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 945273 + ... + 961594.

It is an arithmetic number, because the mean of its divisors is an integer number (3890964154).

Almost surely, 2^15561941587 is an apocalyptic number.

15561941587 is a deficient number, since it is larger than the sum of its proper divisors (1915029).

15561941587 is an equidigital number, since it uses as much as digits as its factorization.

15561941587 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1915028.

The product of its digits is 1512000, while the sum is 52.

The spelling of 15561941587 in words is "fifteen billion, five hundred sixty-one million, nine hundred forty-one thousand, five hundred eighty-seven".