12121650 has 120 divisors (see below), whose sum is σ = 34974324. Its totient is φ = 3110400.

The previous prime is 12121631. The next prime is 12121661. The reversal of 12121650 is 5612121.

12121650 is a `hidden beast` number, since 1 + 2 + 12 + 1 + 650 = 666.

It can be written as a sum of positive squares in 6 ways, for example, as 1798281 + 10323369 = 1341^2 + 3213^2 .

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an alternating number because its digits alternate between odd and even.

It is a Curzon number.

It is a congruent number.

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 59 ways as a sum of consecutive naturals, for example, 166014 + ... + 166086.

Almost surely, 2^12121650 is an apocalyptic number.

12121650 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 12121650, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (17487162).

12121650 is an abundant number, since it is smaller than the sum of its proper divisors (22852674).

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

12121650 is a wasteful number, since it uses less digits than its factorization.

12121650 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138 (or 124 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 18.

The square root of 12121650 is about 3481.6160040992. The cubic root of 12121650 is about 229.7138849323.

Adding to 12121650 its reverse (5612121), we get a palindrome (17733771).

The spelling of 12121650 in words is "twelve million, one hundred twenty-one thousand, six hundred fifty".