121121656 has 16 divisors (see below), whose sum is σ = 239056200. Its totient is φ = 57373344.

The previous prime is 121121647. The next prime is 121121659. The reversal of 121121656 is 656121121.

It is a happy number.

It is a self number, because there is not a number n which added to its sum of digits gives 121121656.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121121659) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 398275 + ... + 398578.

Almost surely, 2^121121656 is an apocalyptic number.

It is an amenable number.

121121656 is a deficient number, since it is larger than the sum of its proper divisors (117934544).

121121656 is a wasteful number, since it uses less digits than its factorization.

121121656 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 796878 (or 796874 counting only the distinct ones).

The product of its digits is 720, while the sum is 25.

The square root of 121121656 is about 11005.5284289306. The cubic root of 121121656 is about 494.7744522217.

Adding to 121121656 its reverse (656121121), we get a palindrome (777242777).

The spelling of 121121656 in words is "one hundred twenty-one million, one hundred twenty-one thousand, six hundred fifty-six".