15981559 has 12 divisors (see below), whose sum is σ = 17667720. Its totient is φ = 14445200.

The previous prime is 15981557. The next prime is 15981593. The reversal of 15981559 is 95518951.

It is not a de Polignac number, because 15981559 - 2¹ = 15981557 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 (15981557) 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 11 ways as a sum of consecutive naturals, for example, 32304 + ... + 32794.

It is an arithmetic number, because the mean of its divisors is an integer number (1472310).

Almost surely, 2^15981559 is an apocalyptic number.

15981559 is a deficient number, since it is larger than the sum of its proper divisors (1686161).

15981559 is a wasteful number, since it uses less digits than its factorization.

15981559 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 782 (or 771 counting only the distinct ones).

The product of its digits is 81000, while the sum is 43.

The square root of 15981559 is about 3997.6942104168. The cubic root of 15981559 is about 251.8873635786.

It can be divided in two parts, 159 and 81559, that added together give a palindrome (81718).

The spelling of 15981559 in words is "fifteen million, nine hundred eighty-one thousand, five hundred fifty-nine".