15361561 has 4 divisors (see below), whose sum is σ = 15891300. Its totient is φ = 14831824.

The previous prime is 15361553. The next prime is 15361571. The reversal of 15361561 is 16516351.

15361561 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, and also an emirpimes, since its reverse is a distinct semiprime: 16516351 = 431 ⋅38321.

It can be written as a sum of positive squares in 2 ways, for example, as 5089536 + 10272025 = 2256^2 + 3205^2 .

It is a cyclic number.

It is not a de Polignac number, because 15361561 - 2³ = 15361553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (15361531) 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, 264826 + ... + 264883.

It is an arithmetic number, because the mean of its divisors is an integer number (3972825).

Almost surely, 2^15361561 is an apocalyptic number.

It is an amenable number.

15361561 is a deficient number, since it is larger than the sum of its proper divisors (529739).

15361561 is an equidigital number, since it uses as much as digits as its factorization.

15361561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 529738.

The product of its digits is 2700, while the sum is 28.

The square root of 15361561 is about 3919.3827320128. The cubic root of 15361561 is about 248.5870210069.

The spelling of 15361561 in words is "fifteen million, three hundred sixty-one thousand, five hundred sixty-one".