2543621 has 2 divisors, whose sum is σ = 2543622. Its totient is φ = 2543620.

The previous prime is 2543617. The next prime is 2543623. The reversal of 2543621 is 1263452.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1464100 + 1079521 = 1210^2 + 1039^2 .

It is a cyclic number.

It is not a de Polignac number, because 2543621 - 2² = 2543617 is a prime.

Together with 2543623, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2543623) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1271810 + 1271811.

It is an arithmetic number, because the mean of its divisors is an integer number (1271811).

2^2543621 is an apocalyptic number.

It is an amenable number.

2543621 is a deficient number, since it is larger than the sum of its proper divisors (1).

2543621 is an equidigital number, since it uses as much as digits as its factorization.

2543621 is an evil number, because the sum of its binary digits is even.

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

The square root of 2543621 is about 1594.8733492036. The cubic root of 2543621 is about 136.5057044761.

The spelling of 2543621 in words is "two million, five hundred forty-three thousand, six hundred twenty-one".