17981998 has 16 divisors (see below), whose sum is σ = 28803456. Its totient is φ = 8399160.

The previous prime is 17981993. The next prime is 17982011. The reversal of 17981998 is 89918971.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (17981993) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 2568 + ... + 6523.

It is an arithmetic number, because the mean of its divisors is an integer number (1800216).

Almost surely, 2^17981998 is an apocalyptic number.

17981998 is a deficient number, since it is larger than the sum of its proper divisors (10821458).

17981998 is a wasteful number, since it uses less digits than its factorization.

17981998 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9159.

The product of its digits is 326592, while the sum is 52.

The square root of 17981998 is about 4240.5186003601. The cubic root of 17981998 is about 261.9867425260.

The spelling of 17981998 in words is "seventeen million, nine hundred eighty-one thousand, nine hundred ninety-eight".