18679988 has 12 divisors (see below), whose sum is σ = 32834340. Its totient is φ = 9298752.

The previous prime is 18679987. The next prime is 18679993. The reversal of 18679988 is 88997681.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 14303524 + 4376464 = 3782^2 + 2092^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18679987) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 9281 + ... + 11112.

It is an arithmetic number, because the mean of its divisors is an integer number (2736195).

Almost surely, 2^18679988 is an apocalyptic number.

It is an amenable number.

18679988 is a deficient number, since it is larger than the sum of its proper divisors (14154352).

18679988 is a wasteful number, since it uses less digits than its factorization.

18679988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 20626 (or 20624 counting only the distinct ones).

The product of its digits is 1741824, while the sum is 56.

The square root of 18679988 is about 4322.0351687602. The cubic root of 18679988 is about 265.3335683160. Note that the first 3 decimals are identical.

The spelling of 18679988 in words is "eighteen million, six hundred seventy-nine thousand, nine hundred eighty-eight".