18666697 has 12 divisors (see below), whose sum is σ = 22992660. Its totient is φ = 15058176.

The previous prime is 18666677. The next prime is 18666707. The reversal of 18666697 is 79666681.

It can be written as a sum of positive squares in 2 ways, for example, as 12595401 + 6071296 = 3549^2 + 2464^2 .

It is not a de Polignac number, because 18666697 - 2¹¹ = 18664649 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (49).

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 18666697.

It is not an unprimeable number, because it can be changed into a prime (18666647) 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, 10372 + ... + 12037.

It is an arithmetic number, because the mean of its divisors is an integer number (1916055).

Almost surely, 2^18666697 is an apocalyptic number.

18666697 is a gapful number since it is divisible by the number (17) formed by its first and last digit.

It is an amenable number.

18666697 is a deficient number, since it is larger than the sum of its proper divisors (4325963).

18666697 is a wasteful number, since it uses less digits than its factorization.

18666697 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22440 (or 22433 counting only the distinct ones).

The product of its digits is 653184, while the sum is 49.

The square root of 18666697 is about 4320.4973093384. The cubic root of 18666697 is about 265.2706242145.

The spelling of 18666697 in words is "eighteen million, six hundred sixty-six thousand, six hundred ninety-seven".