18691066 has 8 divisors (see below), whose sum is σ = 28420884. Its totient is φ = 9217440.

The previous prime is 18691063. The next prime is 18691091. The reversal of 18691066 is 66019681.

It can be written as a sum of positive squares in 2 ways, for example, as 17816841 + 874225 = 4221^2 + 935^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not an unprimeable number, because it can be changed into a prime (18691063) 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, 63865 + ... + 64156.

Almost surely, 2^18691066 is an apocalyptic number.

18691066 is a deficient number, since it is larger than the sum of its proper divisors (9729818).

18691066 is a wasteful number, since it uses less digits than its factorization.

18691066 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 128096.

The product of its (nonzero) digits is 15552, while the sum is 37.

The square root of 18691066 is about 4323.3165509826. The cubic root of 18691066 is about 265.3860091849.

The spelling of 18691066 in words is "eighteen million, six hundred ninety-one thousand, sixty-six".