15910561 has 4 divisors (see below), whose sum is σ = 15956500. Its totient is φ = 15864624.

The previous prime is 15910553. The next prime is 15910567. The reversal of 15910561 is 16501951.

15910561 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 7529536 + 8381025 = 2744^2 + 2895^2 .

It is a cyclic number.

It is not a de Polignac number, because 15910561 - 2³ = 15910553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15910567) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 22446 + ... + 23143.

It is an arithmetic number, because the mean of its divisors is an integer number (3989125).

Almost surely, 2^15910561 is an apocalyptic number.

It is an amenable number.

15910561 is a deficient number, since it is larger than the sum of its proper divisors (45939).

15910561 is an equidigital number, since it uses as much as digits as its factorization.

15910561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 45938.

The product of its (nonzero) digits is 1350, while the sum is 28.

The square root of 15910561 is about 3988.8044574785. The cubic root of 15910561 is about 251.5138070512.

It can be divided in two parts, 15910 and 561, that added together give a triangular number (16471 = T₁₈₁).

The spelling of 15910561 in words is "fifteen million, nine hundred ten thousand, five hundred sixty-one".