1561546241 has 4 divisors (see below), whose sum is σ = 1561828800. Its totient is φ = 1561263684.

The previous prime is 1561546211. The next prime is 1561546243. The reversal of 1561546241 is 1426451651.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 1426451651 = 23 ⋅62019637.

It is a cyclic number.

It is not a de Polignac number, because 1561546241 - 2⁶ = 1561546177 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1561546243) 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, 132821 + ... + 144098.

It is an arithmetic number, because the mean of its divisors is an integer number (390457200).

Almost surely, 2^1561546241 is an apocalyptic number.

It is an amenable number.

1561546241 is a deficient number, since it is larger than the sum of its proper divisors (282559).

1561546241 is an equidigital number, since it uses as much as digits as its factorization.

1561546241 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 282558.

The product of its digits is 28800, while the sum is 35.

The square root of 1561546241 is about 39516.4047074123. The cubic root of 1561546241 is about 1160.1610559671.

Adding to 1561546241 its reverse (1426451651), we get a palindrome (2987997892).

The spelling of 1561546241 in words is "one billion, five hundred sixty-one million, five hundred forty-six thousand, two hundred forty-one".