18649805 has 4 divisors (see below), whose sum is σ = 22379772. Its totient is φ = 14919840.

The previous prime is 18649789. The next prime is 18649819. The reversal of 18649805 is 50894681.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 13645636 + 5004169 = 3694^2 + 2237^2 .

It is not a de Polignac number, because 18649805 - 2⁴ = 18649789 is a prime.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1864976 + ... + 1864985.

It is an arithmetic number, because the mean of its divisors is an integer number (5594943).

Almost surely, 2^18649805 is an apocalyptic number.

It is an amenable number.

18649805 is a deficient number, since it is larger than the sum of its proper divisors (3729967).

18649805 is an equidigital number, since it uses as much as digits as its factorization.

18649805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3729966.

The product of its (nonzero) digits is 69120, while the sum is 41.

The square root of 18649805 is about 4318.5419993326. The cubic root of 18649805 is about 265.1905832069.

The spelling of 18649805 in words is "eighteen million, six hundred forty-nine thousand, eight hundred five".