18993005 has 6 divisors (see below), whose sum is σ = 22803306. Its totient is φ = 15186608.

The previous prime is 18993001. The next prime is 18993017. The reversal of 18993005 is 50039981.

It can be written as a sum of positive squares in 3 ways, for example, as 6959044 + 12033961 = 2638^2 + 3469^2 .

It is not a de Polignac number, because 18993005 - 2² = 18993001 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 (18993001) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 8771 + ... + 10719.

It is an arithmetic number, because the mean of its divisors is an integer number (3800551).

Almost surely, 2^18993005 is an apocalyptic number.

It is an amenable number.

18993005 is a deficient number, since it is larger than the sum of its proper divisors (3810301).

18993005 is an frugal number, since it uses more digits than its factorization.

18993005 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3903 (or 1954 counting only the distinct ones).

The product of its (nonzero) digits is 9720, while the sum is 35.

The square root of 18993005 is about 4358.0964881471. The cubic root of 18993005 is about 266.8074144150.

The spelling of 18993005 in words is "eighteen million, nine hundred ninety-three thousand, five".