15985040 has 20 divisors (see below), whose sum is σ = 37165404. Its totient is φ = 6393984.

The previous prime is 15985033. The next prime is 15985043. The reversal of 15985040 is 4058951.

It can be written as a sum of positive squares in 2 ways, for example, as 12730624 + 3254416 = 3568^2 + 1804^2 .

It is a tau number, because it is divible by the number of its divisors (20).

It is a junction number, because it is equal to n+sod(n) for n = 15984988 and 15985006.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15985043) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 99827 + ... + 99986.

Almost surely, 2^15985040 is an apocalyptic number.

15985040 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

15985040 is an abundant number, since it is smaller than the sum of its proper divisors (21180364).

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

15985040 is a wasteful number, since it uses less digits than its factorization.

15985040 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 199826 (or 199820 counting only the distinct ones).

The product of its (nonzero) digits is 7200, while the sum is 32.

The square root of 15985040 is about 3998.1295626830. The cubic root of 15985040 is about 251.9056504107.

The spelling of 15985040 in words is "fifteen million, nine hundred eighty-five thousand, forty".