18640811 has 8 divisors (see below), whose sum is σ = 21757440. Its totient is φ = 15637608.

The previous prime is 18640777. The next prime is 18640813. The reversal of 18640811 is 11804681.

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

It is not a de Polignac number, because 18640811 - 2¹⁰ = 18639787 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (18640813) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 28001 + ... + 28658.

It is an arithmetic number, because the mean of its divisors is an integer number (2719680).

Almost surely, 2^18640811 is an apocalyptic number.

18640811 is a deficient number, since it is larger than the sum of its proper divisors (3116629).

18640811 is an equidigital number, since it uses as much as digits as its factorization.

18640811 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 56713.

The product of its (nonzero) digits is 1536, while the sum is 29.

The square root of 18640811 is about 4317.5005500868. The cubic root of 18640811 is about 265.1479463425.

The spelling of 18640811 in words is "eighteen million, six hundred forty thousand, eight hundred eleven".