18661797 has 36 divisors (see below), whose sum is σ = 34216416. Its totient is φ = 9691920.

The previous prime is 18661771. The next prime is 18661807. The reversal of 18661797 is 79716681.

It is not a de Polignac number, because 18661797 - 2¹⁵ = 18629029 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18661697) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 35 ways as a sum of consecutive naturals, for example, 2928 + ... + 6774.

It is an arithmetic number, because the mean of its divisors is an integer number (950456).

Almost surely, 2^18661797 is an apocalyptic number.

It is an amenable number.

18661797 is a deficient number, since it is larger than the sum of its proper divisors (15554619).

18661797 is a wasteful number, since it uses less digits than its factorization.

18661797 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3878 (or 3868 counting only the distinct ones).

The product of its digits is 127008, while the sum is 45.

The square root of 18661797 is about 4319.9302077696. The cubic root of 18661797 is about 265.2474110414.

It can be divided in two parts, 1866 and 1797, that added together give a palindrome (3663).

The spelling of 18661797 in words is "eighteen million, six hundred sixty-one thousand, seven hundred ninety-seven".