18181457 has 16 divisors (see below), whose sum is σ = 21245952. Its totient is φ = 15238800.

The previous prime is 18181439. The next prime is 18181507. The reversal of 18181457 is 75418181.

18181457 is nontrivially palindromic in base 2.

It is a cyclic number.

It is not a de Polignac number, because 18181457 - 2¹⁰ = 18180433 is a prime.

It is not an unprimeable number, because it can be changed into a prime (18181417) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 108788 + ... + 108954.

It is an arithmetic number, because the mean of its divisors is an integer number (1327872).

Almost surely, 2^18181457 is an apocalyptic number.

It is an amenable number.

18181457 is a deficient number, since it is larger than the sum of its proper divisors (3064495).

18181457 is a wasteful number, since it uses less digits than its factorization.

18181457 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 428.

The product of its digits is 8960, while the sum is 35.

The square root of 18181457 is about 4263.9719745796. The cubic root of 18181457 is about 262.9518482304.

The spelling of 18181457 in words is "eighteen million, one hundred eighty-one thousand, four hundred fifty-seven".