18729018 has 48 divisors (see below), whose sum is σ = 50596416. Its totient is φ = 4864320.

The previous prime is 18728977. The next prime is 18729023. The reversal of 18729018 is 81092781.

It is a super-2 number, since 2×18729018² = 701552230488648, which contains 22 as substring.

It is an alternating number because its digits alternate between odd and even.

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 5371 + ... + 8142.

It is an arithmetic number, because the mean of its divisors is an integer number (1054092).

Almost surely, 2^18729018 is an apocalyptic number.

18729018 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

18729018 is an abundant number, since it is smaller than the sum of its proper divisors (31867398).

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

18729018 is a wasteful number, since it uses less digits than its factorization.

18729018 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13539 (or 13536 counting only the distinct ones).

The product of its (nonzero) digits is 8064, while the sum is 36.

The square root of 18729018 is about 4327.7035480726. The cubic root of 18729018 is about 265.5655088546.

The spelling of 18729018 in words is "eighteen million, seven hundred twenty-nine thousand, eighteen".