24997561 has 4 divisors (see below), whose sum is σ = 25529472. Its totient is φ = 24465652.

The previous prime is 24997549. The next prime is 24997571. The reversal of 24997561 is 16579942.

It is a happy number.

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.

It is a cyclic number.

It is not a de Polignac number, because 24997561 - 2⁷ = 24997433 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (24997541) 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, 265885 + ... + 265978.

It is an arithmetic number, because the mean of its divisors is an integer number (6382368).

Almost surely, 2^24997561 is an apocalyptic number.

It is an amenable number.

24997561 is a deficient number, since it is larger than the sum of its proper divisors (531911).

24997561 is an equidigital number, since it uses as much as digits as its factorization.

24997561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 531910.

The product of its digits is 136080, while the sum is 43.

The square root of 24997561 is about 4999.7560940510. The cubic root of 24997561 is about 292.3922646064.

The spelling of 24997561 in words is "twenty-four million, nine hundred ninety-seven thousand, five hundred sixty-one".