121216213 has 4 divisors (see below), whose sum is σ = 124172748. Its totient is φ = 118259680.

The previous prime is 121216189. The next prime is 121216217. The reversal of 121216213 is 312612121.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 30547729 + 90668484 = 5527^2 + 9522^2 .

It is a cyclic number.

It is not a de Polignac number, because 121216213 - 2¹⁷ = 121085141 is a prime.

It is a super-2 number, since 2×121216213² = 29386740588122738, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (121216217) 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, 1478206 + ... + 1478287.

It is an arithmetic number, because the mean of its divisors is an integer number (31043187).

Almost surely, 2^121216213 is an apocalyptic number.

It is an amenable number.

121216213 is a deficient number, since it is larger than the sum of its proper divisors (2956535).

121216213 is an equidigital number, since it uses as much as digits as its factorization.

121216213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2956534.

The product of its digits is 144, while the sum is 19.

The square root of 121216213 is about 11009.8234772407. The cubic root of 121216213 is about 494.9031718913.

Adding to 121216213 its reverse (312612121), we get a palindrome (433828334).

The spelling of 121216213 in words is "one hundred twenty-one million, two hundred sixteen thousand, two hundred thirteen".