15661271 has 4 divisors (see below), whose sum is σ = 15670032. Its totient is φ = 15652512.

The previous prime is 15661223. The next prime is 15661273. The reversal of 15661271 is 17216651.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-15661271 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 (15661273) 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, 626 + ... + 5631.

It is an arithmetic number, because the mean of its divisors is an integer number (3917508).

Almost surely, 2^15661271 is an apocalyptic number.

15661271 is a deficient number, since it is larger than the sum of its proper divisors (8761).

15661271 is an equidigital number, since it uses as much as digits as its factorization.

15661271 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8760.

The product of its digits is 2520, while the sum is 29.

The square root of 15661271 is about 3957.4323746591. The cubic root of 15661271 is about 250.1932958417.

The spelling of 15661271 in words is "fifteen million, six hundred sixty-one thousand, two hundred seventy-one".