216610121 has 16 divisors (see below), whose sum is σ = 268090368. Its totient is φ = 170424000.

The previous prime is 216610111. The next prime is 216610123. The reversal of 216610121 is 121016612.

216610121 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-216610121 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 216610093 and 216610102.

It is not an unprimeable number, because it can be changed into a prime (216610123) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 9896 + ... + 23046.

It is an arithmetic number, because the mean of its divisors is an integer number (16755648).

Almost surely, 2^216610121 is an apocalyptic number.

It is an amenable number.

216610121 is a deficient number, since it is larger than the sum of its proper divisors (51480247).

216610121 is a wasteful number, since it uses less digits than its factorization.

216610121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13352.

The product of its (nonzero) digits is 144, while the sum is 20.

The square root of 216610121 is about 14717.6805577509. The cubic root of 216610121 is about 600.5643957811.

Adding to 216610121 its reverse (121016612), we get a palindrome (337626733).

The spelling of 216610121 in words is "two hundred sixteen million, six hundred ten thousand, one hundred twenty-one".