18983917 has 4 divisors (see below), whose sum is σ = 20100636. Its totient is φ = 17867200.

The previous prime is 18983897. The next prime is 18983927. The reversal of 18983917 is 71938981.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 71938981 = 313 ⋅229837.

It can be written as a sum of positive squares in 2 ways, for example, as 16760836 + 2223081 = 4094^2 + 1491^2 .

It is a cyclic number.

It is not a de Polignac number, because 18983917 - 2¹⁹ = 18459629 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 (18983927) 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, 558334 + ... + 558367.

It is an arithmetic number, because the mean of its divisors is an integer number (5025159).

Almost surely, 2^18983917 is an apocalyptic number.

18983917 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

18983917 is a deficient number, since it is larger than the sum of its proper divisors (1116719).

18983917 is a wasteful number, since it uses less digits than its factorization.

18983917 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1116718.

The product of its digits is 108864, while the sum is 46.

The square root of 18983917 is about 4357.0537063479. The cubic root of 18983917 is about 266.7648525591.

It can be divided in two parts, 18983 and 917, that added together give a triangular number (19900 = T₁₉₉).

The spelling of 18983917 in words is "eighteen million, nine hundred eighty-three thousand, nine hundred seventeen".