18778945 has 8 divisors (see below), whose sum is σ = 22619520. Its totient is φ = 14966640.

The previous prime is 18778939. The next prime is 18778951. The reversal of 18778945 is 54987781.

It is an interprime number because it is at equal distance from previous prime (18778939) and next prime (18778951).

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

It is not a de Polignac number, because 18778945 - 2³ = 18778937 is a prime.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5575 + ... + 8284.

It is an arithmetic number, because the mean of its divisors is an integer number (2827440).

Almost surely, 2^18778945 is an apocalyptic number.

It is an amenable number.

18778945 is a deficient number, since it is larger than the sum of its proper divisors (3840575).

18778945 is a wasteful number, since it uses less digits than its factorization.

18778945 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14135.

The product of its digits is 564480, while the sum is 49.

The square root of 18778945 is about 4333.4680107277. The cubic root of 18778945 is about 265.8012771318.

The spelling of 18778945 in words is "eighteen million, seven hundred seventy-eight thousand, nine hundred forty-five".