216013121 has 4 divisors (see below), whose sum is σ = 216426672. Its totient is φ = 215599572.

The previous prime is 216013117. The next prime is 216013129. The reversal of 216013121 is 121310612.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 216013121 - 2² = 216013117 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 216013121.

It is not an unprimeable number, because it can be changed into a prime (216013129) 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, 205991 + ... + 207036.

It is an arithmetic number, because the mean of its divisors is an integer number (54106668).

Almost surely, 2^216013121 is an apocalyptic number.

It is an amenable number.

216013121 is a deficient number, since it is larger than the sum of its proper divisors (413551).

216013121 is an equidigital number, since it uses as much as digits as its factorization.

216013121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 413550.

The product of its (nonzero) digits is 72, while the sum is 17.

The square root of 216013121 is about 14697.3848354052. The cubic root of 216013121 is about 600.0121488281.

Adding to 216013121 its reverse (121310612), we get a palindrome (337323733).

The spelling of 216013121 in words is "two hundred sixteen million, thirteen thousand, one hundred twenty-one".