18940493 has 12 divisors (see below), whose sum is σ = 22422204. Its totient is φ = 15892800.

The previous prime is 18940489. The next prime is 18940513. The reversal of 18940493 is 39404981.

It can be written as a sum of positive squares in 2 ways, for example, as 7086244 + 11854249 = 2662^2 + 3443^2 .

It is not a de Polignac number, because 18940493 - 2² = 18940489 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18940423) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4448 + ... + 7593.

It is an arithmetic number, because the mean of its divisors is an integer number (1868517).

Almost surely, 2^18940493 is an apocalyptic number.

18940493 is a gapful number since it is divisible by the number (13) formed by its first and last digit.

It is an amenable number.

18940493 is a deficient number, since it is larger than the sum of its proper divisors (3481711).

18940493 is a wasteful number, since it uses less digits than its factorization.

18940493 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12076 (or 12065 counting only the distinct ones).

The product of its (nonzero) digits is 31104, while the sum is 38.

The square root of 18940493 is about 4352.0676695107. The cubic root of 18940493 is about 266.5612970855.

The spelling of 18940493 in words is "eighteen million, nine hundred forty thousand, four hundred ninety-three".