18131512 has 64 divisors (see below), whose sum is σ = 40824000. Its totient is φ = 7388160.

The previous prime is 18131507. The next prime is 18131551. The reversal of 18131512 is 21513181.

It is a super-2 number, since 2×18131512² = 657503454812288, which contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 121614 + ... + 121762.

It is an arithmetic number, because the mean of its divisors is an integer number (637875).

Almost surely, 2^18131512 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 18131512, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (20412000).

18131512 is an abundant number, since it is smaller than the sum of its proper divisors (22692488).

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

18131512 is a wasteful number, since it uses less digits than its factorization.

18131512 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 256 (or 252 counting only the distinct ones).

The product of its digits is 240, while the sum is 22.

The square root of 18131512 is about 4258.1113184134. Note that the first 3 decimals coincide. The cubic root of 18131512 is about 262.7108485836.

Adding to 18131512 its reverse (21513181), we get a palindrome (39644693).

The spelling of 18131512 in words is "eighteen million, one hundred thirty-one thousand, five hundred twelve".