12161900 has 72 divisors (see below), whose sum is σ = 28696080. Its totient is φ = 4458240.

The previous prime is 12161899. The next prime is 12161911. The reversal of 12161900 is 916121.

It is a super-2 number, since 2×12161900² = 295823623220000, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (20).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 70214 + ... + 70386.

Almost surely, 2^12161900 is an apocalyptic number.

12161900 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 12161900, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (14348040).

12161900 is an abundant number, since it is smaller than the sum of its proper divisors (16534180).

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

12161900 is a wasteful number, since it uses less digits than its factorization.

12161900 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 243 (or 236 counting only the distinct ones).

The product of its (nonzero) digits is 108, while the sum is 20.

The square root of 12161900 is about 3487.3915753755. The cubic root of 12161900 is about 229.9678594030.

It can be divided in two parts, 1216 and 1900, that multiplied together give a square (2310400 = 1520²).

The spelling of 12161900 in words is "twelve million, one hundred sixty-one thousand, nine hundred".