2215121 has 4 divisors (see below), whose sum is σ = 2240100. Its totient is φ = 2190144.

The previous prime is 2215111. The next prime is 2215127. The reversal of 2215121 is 1215122.

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 144400 + 2070721 = 380^2 + 1439^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2215121 is a prime.

It is a super-2 number, since 2×2215121² = 9813522089282, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2215096 and 2215105.

It is not an unprimeable number, because it can be changed into a prime (2215127) 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, 12356 + ... + 12533.

It is an arithmetic number, because the mean of its divisors is an integer number (560025).

2^2215121 is an apocalyptic number.

It is an amenable number.

2215121 is a deficient number, since it is larger than the sum of its proper divisors (24979).

2215121 is an equidigital number, since it uses as much as digits as its factorization.

2215121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 24978.

The product of its digits is 40, while the sum is 14.

The square root of 2215121 is about 1488.3282568036. The cubic root of 2215121 is about 130.3564379878.

Subtracting from 2215121 its reverse (1215122), we obtain a palindrome (999999).

The spelling of 2215121 in words is "two million, two hundred fifteen thousand, one hundred twenty-one".