18661267 has 4 divisors (see below), whose sum is σ = 18670000. Its totient is φ = 18652536.

The previous prime is 18661259. The next prime is 18661271. The reversal of 18661267 is 76216681.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 76216681 = 163 ⋅467587.

It is a cyclic number.

It is not a de Polignac number, because 18661267 - 2³ = 18661259 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18661217) 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, 1234 + ... + 6232.

It is an arithmetic number, because the mean of its divisors is an integer number (4667500).

Almost surely, 2^18661267 is an apocalyptic number.

18661267 is a deficient number, since it is larger than the sum of its proper divisors (8733).

18661267 is an equidigital number, since it uses as much as digits as its factorization.

18661267 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8732.

The product of its digits is 24192, while the sum is 37.

The square root of 18661267 is about 4319.8688637504. The cubic root of 18661267 is about 265.2448999852.

The spelling of 18661267 in words is "eighteen million, six hundred sixty-one thousand, two hundred sixty-seven".