2643521 has 4 divisors (see below), whose sum is σ = 2657412. Its totient is φ = 2629632.

The previous prime is 2643497. The next prime is 2643523. The reversal of 2643521 is 1253462.

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 287296 + 2356225 = 536^2 + 1535^2 .

It is a cyclic number.

It is not a de Polignac number, because 2643521 - 2⁶ = 2643457 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 (2643523) 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, 6656 + ... + 7041.

It is an arithmetic number, because the mean of its divisors is an integer number (664353).

2^2643521 is an apocalyptic number.

It is an amenable number.

2643521 is a deficient number, since it is larger than the sum of its proper divisors (13891).

2643521 is a wasteful number, since it uses less digits than its factorization.

2643521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 13890.

The product of its digits is 1440, while the sum is 23.

The square root of 2643521 is about 1625.8908327437. The cubic root of 2643521 is about 138.2698807393.

Adding to 2643521 its reverse (1253462), we get a palindrome (3896983).

The spelling of 2643521 in words is "two million, six hundred forty-three thousand, five hundred twenty-one".