12111900 has 72 divisors (see below), whose sum is σ = 35831040. Its totient is φ = 3157440.

The previous prime is 12111899. The next prime is 12111901. The reversal of 12111900 is 911121.

It is an interprime number because it is at equal distance from previous prime (12111899) and next prime (12111901).

It is a super-2 number, since 2×12111900² = 293396243220000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (15).

It is a self number, because there is not a number n which added to its sum of digits gives 12111900.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12111901) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 13671 + ... + 14529.

Almost surely, 2^12111900 is an apocalyptic number.

12111900 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 12111900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (17915520).

12111900 is an abundant number, since it is smaller than the sum of its proper divisors (23719140).

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

12111900 is a wasteful number, since it uses less digits than its factorization.

12111900 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 923 (or 916 counting only the distinct ones).

The product of its (nonzero) digits is 18, while the sum is 15.

The square root of 12111900 is about 3480.2155105683. The cubic root of 12111900 is about 229.6522786013.

It can be divided in two parts, 121 and 11900, that added together give a palindrome (12021).

The spelling of 12111900 in words is "twelve million, one hundred eleven thousand, nine hundred".