18688988 has 12 divisors (see below), whose sum is σ = 32765040. Its totient is φ = 9327552.

The previous prime is 18688981. The next prime is 18688991. The reversal of 18688988 is 88988681.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18688981) 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, 1568 + ... + 6311.

It is an arithmetic number, because the mean of its divisors is an integer number (2730420).

Almost surely, 2^18688988 is an apocalyptic number.

It is an amenable number.

18688988 is a deficient number, since it is larger than the sum of its proper divisors (14076052).

18688988 is a wasteful number, since it uses less digits than its factorization.

18688988 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8476 (or 8474 counting only the distinct ones).

The product of its digits is 1769472, while the sum is 56.

The square root of 18688988 is about 4323.0762195455. The cubic root of 18688988 is about 265.3761739591.

The spelling of 18688988 in words is "eighteen million, six hundred eighty-eight thousand, nine hundred eighty-eight".