18457561 has 8 divisors (see below), whose sum is σ = 19046664. Its totient is φ = 17873280.

The previous prime is 18457547. The next prime is 18457573. The reversal of 18457561 is 16575481.

It can be written as a sum of positive squares in 4 ways, for example, as 8497225 + 9960336 = 2915^2 + 3156^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 18457561 - 2⁷ = 18457433 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (37).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18457561.

It is not an unprimeable number, because it can be changed into a prime (18457541) 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 7 ways as a sum of consecutive naturals, for example, 7551 + ... + 9691.

It is an arithmetic number, because the mean of its divisors is an integer number (2380833).

Almost surely, 2^18457561 is an apocalyptic number.

It is an amenable number.

18457561 is a deficient number, since it is larger than the sum of its proper divisors (589103).

18457561 is a wasteful number, since it uses less digits than its factorization.

18457561 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2411.

The product of its digits is 33600, while the sum is 37.

The square root of 18457561 is about 4296.2263674066. The cubic root of 18457561 is about 264.2762308051.

The spelling of 18457561 in words is "eighteen million, four hundred fifty-seven thousand, five hundred sixty-one".