17994978 has 12 divisors (see below), whose sum is σ = 38989158. Its totient is φ = 5998320.

The previous prime is 17994961. The next prime is 17994979. The reversal of 17994978 is 87949971.

It can be written as a sum of positive squares in only one way, i.e., 17867529 + 127449 = 4227^2 + 357^2 .

It is a super-3 number, since 3×17994978³ (a number of 23 digits) contains 333 as substring.

It is not an unprimeable number, because it can be changed into a prime (17994979) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 499843 + ... + 499878.

Almost surely, 2^17994978 is an apocalyptic number.

17994978 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

17994978 is an abundant number, since it is smaller than the sum of its proper divisors (20994180).

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

17994978 is a wasteful number, since it uses less digits than its factorization.

17994978 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 999729 (or 999726 counting only the distinct ones).

The product of its digits is 1143072, while the sum is 54.

The square root of 17994978 is about 4242.0487974562. The cubic root of 17994978 is about 262.0497642589.

The spelling of 17994978 in words is "seventeen million, nine hundred ninety-four thousand, nine hundred seventy-eight".