18361540 has 24 divisors (see below), whose sum is σ = 38653272. Its totient is φ = 7326720.

The previous prime is 18361493. The next prime is 18361571. The reversal of 18361540 is 4516381.

It can be written as a sum of positive squares in 4 ways, for example, as 5271616 + 13089924 = 2296^2 + 3618^2 .

It is a junction number, because it is equal to n+sod(n) for n = 18361499 and 18361508.

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, 9972 + ... + 11668.

It is an arithmetic number, because the mean of its divisors is an integer number (1610553).

Almost surely, 2^18361540 is an apocalyptic number.

18361540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18361540 is an abundant number, since it is smaller than the sum of its proper divisors (20291732).

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

18361540 is a wasteful number, since it uses less digits than its factorization.

18361540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2247 (or 2245 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 28.

The square root of 18361540 is about 4285.0367559684. The cubic root of 18361540 is about 263.8171560685.

The spelling of 18361540 in words is "eighteen million, three hundred sixty-one thousand, five hundred forty".