2543921 has 2 divisors, whose sum is σ = 2543922. Its totient is φ = 2543920.

The previous prime is 2543917. The next prime is 2543939. The reversal of 2543921 is 1293452.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2002225 + 541696 = 1415^2 + 736^2 .

It is a cyclic number.

It is not a de Polignac number, because 2543921 - 2² = 2543917 is a prime.

It is not a weakly prime, because it can be changed into another prime (2543971) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1271960 + 1271961.

It is an arithmetic number, because the mean of its divisors is an integer number (1271961).

2^2543921 is an apocalyptic number.

It is an amenable number.

2543921 is a deficient number, since it is larger than the sum of its proper divisors (1).

2543921 is an equidigital number, since it uses as much as digits as its factorization.

2543921 is an evil number, because the sum of its binary digits is even.

The product of its digits is 2160, while the sum is 26.

The square root of 2543921 is about 1594.9673977859. The cubic root of 2543921 is about 136.5110708549.

The spelling of 2543921 in words is "two million, five hundred forty-three thousand, nine hundred twenty-one".