18993970 has 16 divisors (see below), whose sum is σ = 34623360. Its totient is φ = 7501104.

The previous prime is 18993967. The next prime is 18993971. The reversal of 18993970 is 7939981.

It is a self number, because there is not a number n which added to its sum of digits gives 18993970.

It is not an unprimeable number, because it can be changed into a prime (18993971) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 11232 + ... + 12811.

It is an arithmetic number, because the mean of its divisors is an integer number (2163960).

Almost surely, 2^18993970 is an apocalyptic number.

18993970 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18993970 is a deficient number, since it is larger than the sum of its proper divisors (15629390).

18993970 is a wasteful number, since it uses less digits than its factorization.

18993970 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24129.

The product of its (nonzero) digits is 122472, while the sum is 46.

The square root of 18993970 is about 4358.2072002143. The cubic root of 18993970 is about 266.8119330047.

The spelling of 18993970 in words is "eighteen million, nine hundred ninety-three thousand, nine hundred seventy".