15728661 has 36 divisors (see below), whose sum is σ = 25579008. Its totient is φ = 9653904.

The previous prime is 15728611. The next prime is 15728681. The reversal of 15728661 is 16682751.

15728661 is a `hidden beast` number, since 1 + 572 + 86 + 6 + 1 = 666.

It is not a de Polignac number, because 15728661 - 2¹³ = 15720469 is a prime.

It is a zygodrome in base 4.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15728611) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 40876 + ... + 41258.

It is an arithmetic number, because the mean of its divisors is an integer number (710528).

Almost surely, 2^15728661 is an apocalyptic number.

It is an amenable number.

15728661 is a deficient number, since it is larger than the sum of its proper divisors (9850347).

15728661 is an equidigital number, since it uses as much as digits as its factorization.

15728661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 424 (or 399 counting only the distinct ones).

The product of its digits is 20160, while the sum is 36.

The square root of 15728661 is about 3965.9375940627. The cubic root of 15728661 is about 250.5516405422.

The spelling of 15728661 in words is "fifteen million, seven hundred twenty-eight thousand, six hundred sixty-one".