18439453 has 4 divisors (see below), whose sum is σ = 18602748. Its totient is φ = 18276160.

The previous prime is 18439439. The next prime is 18439457. The reversal of 18439453 is 35493481.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 35493481 = 31 ⋅1144951.

It can be written as a sum of positive squares in 2 ways, for example, as 444889 + 17994564 = 667^2 + 4242^2 .

It is a cyclic number.

It is not a de Polignac number, because 18439453 - 2⁹ = 18438941 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18439457) 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 3 ways as a sum of consecutive naturals, for example, 81478 + ... + 81703.

It is an arithmetic number, because the mean of its divisors is an integer number (4650687).

Almost surely, 2^18439453 is an apocalyptic number.

It is an amenable number.

18439453 is a deficient number, since it is larger than the sum of its proper divisors (163295).

18439453 is a wasteful number, since it uses less digits than its factorization.

18439453 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 163294.

The product of its digits is 51840, while the sum is 37.

The square root of 18439453 is about 4294.1184194198. The cubic root of 18439453 is about 264.1897787941.

The spelling of 18439453 in words is "eighteen million, four hundred thirty-nine thousand, four hundred fifty-three".