18917493 has 16 divisors (see below), whose sum is σ = 29099520. Its totient is φ = 10707696.

The previous prime is 18917491. The next prime is 18917497. The reversal of 18917493 is 39471981.

It is a happy number.

It is not a de Polignac number, because 18917493 - 2¹ = 18917491 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18917491) 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, 1963 + ... + 6456.

It is an arithmetic number, because the mean of its divisors is an integer number (1818720).

Almost surely, 2^18917493 is an apocalyptic number.

It is an amenable number.

18917493 is a deficient number, since it is larger than the sum of its proper divisors (10182027).

18917493 is a wasteful number, since it uses less digits than its factorization.

18917493 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8536.

The product of its digits is 54432, while the sum is 42.

The square root of 18917493 is about 4349.4244446823. The cubic root of 18917493 is about 266.4533556298.

The spelling of 18917493 in words is "eighteen million, nine hundred seventeen thousand, four hundred ninety-three".