18978056 has 8 divisors (see below), whose sum is σ = 35583870. Its totient is φ = 9489024.

The previous prime is 18978053. The next prime is 18978067. The reversal of 18978056 is 65087981.

It is a happy number.

It can be written as a sum of positive squares in only one way, i.e., 18576100 + 401956 = 4310^2 + 634^2 .

It is a tau number, because it is divible by the number of its divisors (8).

It is a junction number, because it is equal to n+sod(n) for n = 18977998 and 18978016.

It is not an unprimeable number, because it can be changed into a prime (18978053) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1186121 + ... + 1186136.

Almost surely, 2^18978056 is an apocalyptic number.

It is an amenable number.

18978056 is a deficient number, since it is larger than the sum of its proper divisors (16605814).

18978056 is a wasteful number, since it uses less digits than its factorization.

18978056 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2372263 (or 2372259 counting only the distinct ones).

The product of its (nonzero) digits is 120960, while the sum is 44.

The square root of 18978056 is about 4356.3810668949. The cubic root of 18978056 is about 266.7373965160.

The spelling of 18978056 in words is "eighteen million, nine hundred seventy-eight thousand, fifty-six".