2156513 has 4 divisors (see below), whose sum is σ = 2162880. Its totient is φ = 2150148.

The previous prime is 2156507. The next prime is 2156521. The reversal of 2156513 is 3156512.

Added to its reverse (3156512) it gives a square (5313025 = 2305²).

2156513 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, 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 2156513 - 2¹⁴ = 2140129 is a prime.

It is a Duffinian number.

It is a Curzon 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, 2645 + ... + 3362.

It is an arithmetic number, because the mean of its divisors is an integer number (540720).

2^2156513 is an apocalyptic number.

It is an amenable number.

2156513 is a deficient number, since it is larger than the sum of its proper divisors (6367).

2156513 is an equidigital number, since it uses as much as digits as its factorization.

2156513 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6366.

The product of its digits is 900, while the sum is 23.

The square root of 2156513 is about 1468.5070650154. The cubic root of 2156513 is about 129.1964836241.

Adding to 2156513 its reverse (3156512), we get a square (5313025 = 2305²).

Subtracting 2156513 from its reverse (3156512), we obtain a palindrome (999999).

It can be divided in two parts, 215651 and 3, that multiplied together give a triangular number (646953 = T₁₁₃₇).

The spelling of 2156513 in words is "two million, one hundred fifty-six thousand, five hundred thirteen".