15981040 has 40 divisors (see below), whose sum is σ = 38167200. Its totient is φ = 6218496.

The previous prime is 15981023. The next prime is 15981047. The reversal of 15981040 is 4018951.

It is a happy number.

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15981047) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 261 + ... + 5659.

It is an arithmetic number, because the mean of its divisors is an integer number (954180).

Almost surely, 2^15981040 is an apocalyptic number.

15981040 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 15981040, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19083600).

15981040 is an abundant number, since it is smaller than the sum of its proper divisors (22186160).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

15981040 is a wasteful number, since it uses less digits than its factorization.

15981040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5449 (or 5443 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 28.

The square root of 15981040 is about 3997.6292974712. The cubic root of 15981040 is about 251.8846368743.

Adding to 15981040 its reverse (4018951), we get a palindrome (19999991).

The spelling of 15981040 in words is "fifteen million, nine hundred eighty-one thousand, forty".