18420170 has 16 divisors (see below), whose sum is σ = 33700968. Its totient is φ = 7247040.

The previous prime is 18420161. The next prime is 18420209. The reversal of 18420170 is 7102481.

It can be written as a sum of positive squares in 4 ways, for example, as 7284601 + 11135569 = 2699^2 + 3337^2 .

It is a Curzon number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 14489 + ... + 15708.

Almost surely, 2^18420170 is an apocalyptic number.

18420170 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

18420170 is a deficient number, since it is larger than the sum of its proper divisors (15280798).

18420170 is a wasteful number, since it uses less digits than its factorization.

18420170 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 30265.

The product of its (nonzero) digits is 448, while the sum is 23.

The square root of 18420170 is about 4291.8725516958. The cubic root of 18420170 is about 264.0976547970.

The spelling of 18420170 in words is "eighteen million, four hundred twenty thousand, one hundred seventy".