18461257 has 4 divisors (see below), whose sum is σ = 18491796. Its totient is φ = 18430720.

The previous prime is 18461243. The next prime is 18461263. The reversal of 18461257 is 75216481.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 75216481 = 89 ⋅845129.

It can be written as a sum of positive squares in 2 ways, for example, as 4999696 + 13461561 = 2236^2 + 3669^2 .

It is a cyclic number.

It is not a de Polignac number, because 18461257 - 2¹¹ = 18459209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18461227) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 14344 + ... + 15577.

It is an arithmetic number, because the mean of its divisors is an integer number (4622949).

Almost surely, 2^18461257 is an apocalyptic number.

It is an amenable number.

18461257 is a deficient number, since it is larger than the sum of its proper divisors (30539).

18461257 is an equidigital number, since it uses as much as digits as its factorization.

18461257 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 30538.

The product of its digits is 13440, while the sum is 34.

The square root of 18461257 is about 4296.6564908077. The cubic root of 18461257 is about 264.2938694621.

The spelling of 18461257 in words is "eighteen million, four hundred sixty-one thousand, two hundred fifty-seven".