18181970 has 16 divisors (see below), whose sum is σ = 32778648. Its totient is φ = 7261440.

The previous prime is 18181967. The next prime is 18181981. The reversal of 18181970 is 7918181.

It can be written as a sum of positive squares in 4 ways, for example, as 12794929 + 5387041 = 3577^2 + 2321^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 18181970.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 8840 + ... + 10700.

Almost surely, 2^18181970 is an apocalyptic number.

18181970 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18181970 is a deficient number, since it is larger than the sum of its proper divisors (14596678).

18181970 is a wasteful number, since it uses less digits than its factorization.

18181970 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2845.

The product of its (nonzero) digits is 4032, while the sum is 35.

The square root of 18181970 is about 4264.0321293349. The cubic root of 18181970 is about 262.9543213184.

The spelling of 18181970 in words is "eighteen million, one hundred eighty-one thousand, nine hundred seventy".