18978075 has 18 divisors (see below), whose sum is σ = 33992244. Its totient is φ = 10121520.

The previous prime is 18978073. The next prime is 18978079. The reversal of 18978075 is 57087981.

It is not a de Polignac number, because 18978075 - 2¹ = 18978073 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a self number, because there is not a number n which added to its sum of digits gives 18978075.

It is not an unprimeable number, because it can be changed into a prime (18978073) by changing a digit.

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 17 ways as a sum of consecutive naturals, for example, 41949 + ... + 42398.

It is an arithmetic number, because the mean of its divisors is an integer number (1888458).

Almost surely, 2^18978075 is an apocalyptic number.

18978075 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

18978075 is a deficient number, since it is larger than the sum of its proper divisors (15014169).

18978075 is a wasteful number, since it uses less digits than its factorization.

18978075 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 84363 (or 84355 counting only the distinct ones).

The product of its (nonzero) digits is 141120, while the sum is 45.

The square root of 18978075 is about 4356.3832476035. The cubic root of 18978075 is about 266.7374855312.

The spelling of 18978075 in words is "eighteen million, nine hundred seventy-eight thousand, seventy-five".