2156213 has 4 divisors (see below), whose sum is σ = 2178540. Its totient is φ = 2133888.

The previous prime is 2156207. The next prime is 2156221. The reversal of 2156213 is 3126512.

2156213 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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 770884 + 1385329 = 878^2 + 1177^2 .

It is a cyclic number.

It is not a de Polignac number, because 2156213 - 2¹⁴ = 2139829 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2156813) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 11018 + ... + 11211.

It is an arithmetic number, because the mean of its divisors is an integer number (544635).

2^2156213 is an apocalyptic number.

It is an amenable number.

2156213 is a deficient number, since it is larger than the sum of its proper divisors (22327).

2156213 is an equidigital number, since it uses as much as digits as its factorization.

2156213 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 22326.

The product of its digits is 360, while the sum is 20.

The square root of 2156213 is about 1468.4049169081. The cubic root of 2156213 is about 129.1904923560.

Subtracting 2156213 from its reverse (3126512), we obtain a cube (970299 = 99³).

It can be divided in two parts, 215 and 6213, that multiplied together give a triangular number (1335795 = T₁₆₃₄).

The spelling of 2156213 in words is "two million, one hundred fifty-six thousand, two hundred thirteen".