213215121 has 18 divisors (see below), whose sum is σ = 358260162. Its totient is φ = 121836960.

The previous prime is 213215099. The next prime is 213215143. The reversal of 213215121 is 121512312.

It is an interprime number because it is at equal distance from previous prime (213215099) and next prime (213215143).

It can be written as a sum of positive squares in only one way, i.e., 206324496 + 6890625 = 14364^2 + 2625^2 .

It is not a de Polignac number, because 213215121 - 2⁵ = 213215089 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 213215094 and 213215103.

It is not an unprimeable number, because it can be changed into a prime (213215521) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 241300 + ... + 242181.

Almost surely, 2^213215121 is an apocalyptic number.

213215121 is a gapful number since it is divisible by the number (21) formed by its first and last digit.

It is an amenable number.

213215121 is a deficient number, since it is larger than the sum of its proper divisors (145045041).

213215121 is a wasteful number, since it uses less digits than its factorization.

213215121 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 483501 (or 483491 counting only the distinct ones).

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

The square root of 213215121 is about 14601.8875834599. The cubic root of 213215121 is about 597.4102463760.

Adding to 213215121 its reverse (121512312), we get a palindrome (334727433).

The spelling of 213215121 in words is "two hundred thirteen million, two hundred fifteen thousand, one hundred twenty-one".