18916805 has 8 divisors (see below), whose sum is σ = 23313912. Its totient is φ = 14724288.

The previous prime is 18916763. The next prime is 18916811. The reversal of 18916805 is 50861981.

It can be written as a sum of positive squares in 4 ways, for example, as 9928801 + 8988004 = 3151^2 + 2998^2 .

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

It is a cyclic number.

It is not a de Polignac number, because 18916805 - 2¹² = 18912709 is a prime.

It is a super-2 number, since 2×18916805² = 715691022816050, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 50942 + ... + 51311.

It is an arithmetic number, because the mean of its divisors is an integer number (2914239).

Almost surely, 2^18916805 is an apocalyptic number.

It is an amenable number.

18916805 is a deficient number, since it is larger than the sum of its proper divisors (4397107).

18916805 is a wasteful number, since it uses less digits than its factorization.

18916805 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102295.

The product of its (nonzero) digits is 17280, while the sum is 38.

The square root of 18916805 is about 4349.3453530388. The cubic root of 18916805 is about 266.4501254250.

The spelling of 18916805 in words is "eighteen million, nine hundred sixteen thousand, eight hundred five".