18158020 has 24 divisors (see below), whose sum is σ = 38657304. Its totient is φ = 7163136.

The previous prime is 18158011. The next prime is 18158029. The reversal of 18158020 is 2085181.

It is an interprime number because it is at equal distance from previous prime (18158011) and next prime (18158029).

It can be written as a sum of positive squares in 4 ways, for example, as 61504 + 18096516 = 248^2 + 4254^2 .

It is not an unprimeable number, because it can be changed into a prime (18158029) 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, 4759 + ... + 7678.

It is an arithmetic number, because the mean of its divisors is an integer number (1610721).

Almost surely, 2^18158020 is an apocalyptic number.

18158020 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18158020 is an abundant number, since it is smaller than the sum of its proper divisors (20499284).

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

18158020 is a wasteful number, since it uses less digits than its factorization.

18158020 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 12519 (or 12517 counting only the distinct ones).

The product of its (nonzero) digits is 640, while the sum is 25.

The square root of 18158020 is about 4261.2228291888. Note that the first 3 decimals coincide. The cubic root of 18158020 is about 262.8388126902.

The spelling of 18158020 in words is "eighteen million, one hundred fifty-eight thousand, twenty".