18671797 has 4 divisors (see below), whose sum is σ = 19770156. Its totient is φ = 17573440.

The previous prime is 18671777. The next prime is 18671801. The reversal of 18671797 is 79717681.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 16966161 + 1705636 = 4119^2 + 1306^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-18671797 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 (18671707) 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, 549154 + ... + 549187.

It is an arithmetic number, because the mean of its divisors is an integer number (4942539).

Almost surely, 2^18671797 is an apocalyptic number.

18671797 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

18671797 is a deficient number, since it is larger than the sum of its proper divisors (1098359).

18671797 is a wasteful number, since it uses less digits than its factorization.

18671797 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1098358.

The product of its digits is 148176, while the sum is 46.

The square root of 18671797 is about 4321.0874788646. The cubic root of 18671797 is about 265.2947805502.

The spelling of 18671797 in words is "eighteen million, six hundred seventy-one thousand, seven hundred ninety-seven".