18878994 has 20 divisors (see below), whose sum is σ = 42303294. Its totient is φ = 6292944.

The previous prime is 18878987. The next prime is 18878999. The reversal of 18878994 is 49987881.

It can be written as a sum of positive squares in only one way, i.e., 10323369 + 8555625 = 3213^2 + 2925^2 .

It is a Harshad number since it is a multiple of its sum of digits (54).

It is a self number, because there is not a number n which added to its sum of digits gives 18878994.

It is not an unprimeable number, because it can be changed into a prime (18878999) by changing a digit.

It is a polite number, since it can be written in 9 ways as a sum of consecutive naturals, for example, 58107 + ... + 58430.

Almost surely, 2^18878994 is an apocalyptic number.

18878994 is an abundant number, since it is smaller than the sum of its proper divisors (23424300).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18878994 is a wasteful number, since it uses less digits than its factorization.

18878994 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 116551 (or 116542 counting only the distinct ones).

The product of its digits is 1161216, while the sum is 54.

The square root of 18878994 is about 4344.9964326798. The cubic root of 18878994 is about 266.2724797524.

The spelling of 18878994 in words is "eighteen million, eight hundred seventy-eight thousand, nine hundred ninety-four".