18531380 has 24 divisors (see below), whose sum is σ = 44475648. Its totient is φ = 6353568.

The previous prime is 18531361. The next prime is 18531389. The reversal of 18531380 is 8313581.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18531389) 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, 66044 + ... + 66323.

It is an arithmetic number, because the mean of its divisors is an integer number (1853152).

Almost surely, 2^18531380 is an apocalyptic number.

18531380 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18531380 is an abundant number, since it is smaller than the sum of its proper divisors (25944268).

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

18531380 is a wasteful number, since it uses less digits than its factorization.

18531380 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 132383 (or 132381 counting only the distinct ones).

The product of its (nonzero) digits is 2880, while the sum is 29.

The square root of 18531380 is about 4304.8089388497. The cubic root of 18531380 is about 264.6280768083.

The spelling of 18531380 in words is "eighteen million, five hundred thirty-one thousand, three hundred eighty".