18039457 has 4 divisors (see below), whose sum is σ = 18154516. Its totient is φ = 17924400.

The previous prime is 18039449. The next prime is 18039491. The reversal of 18039457 is 75493081.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1846881 + 16192576 = 1359^2 + 4024^2 .

It is a cyclic number.

It is not a de Polignac number, because 18039457 - 2³ = 18039449 is a prime.

It is a super-3 number, since 3×18039457³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18039257) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 57294 + ... + 57607.

It is an arithmetic number, because the mean of its divisors is an integer number (4538629).

Almost surely, 2^18039457 is an apocalyptic number.

It is an amenable number.

18039457 is a deficient number, since it is larger than the sum of its proper divisors (115059).

18039457 is a wasteful number, since it uses less digits than its factorization.

18039457 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 115058.

The product of its (nonzero) digits is 30240, while the sum is 37.

The square root of 18039457 is about 4247.2881936596. The cubic root of 18039457 is about 262.2654933605.

It can be divided in two parts, 18039 and 457, that added together give a square (18496 = 136²).

The spelling of 18039457 in words is "eighteen million, thirty-nine thousand, four hundred fifty-seven".