24661561 has 4 divisors (see below), whose sum is σ = 25029712. Its totient is φ = 24293412.

The previous prime is 24661547. The next prime is 24661591. The reversal of 24661561 is 16516642.

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: 16516642 = 2 ⋅8258321.

It is a cyclic number.

It is not a de Polignac number, because 24661561 - 2⁵ = 24661529 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (24661501) 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, 183975 + ... + 184108.

It is an arithmetic number, because the mean of its divisors is an integer number (6257428).

Almost surely, 2^24661561 is an apocalyptic number.

It is an amenable number.

24661561 is a deficient number, since it is larger than the sum of its proper divisors (368151).

24661561 is an equidigital number, since it uses as much as digits as its factorization.

24661561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 368150.

The product of its digits is 8640, while the sum is 31.

The square root of 24661561 is about 4966.0407771181. The cubic root of 24661561 is about 291.0763056509.

The spelling of 24661561 in words is "twenty-four million, six hundred sixty-one thousand, five hundred sixty-one".