2547821 has 2 divisors, whose sum is σ = 2547822. Its totient is φ = 2547820.

The previous prime is 2547817. The next prime is 2547833. The reversal of 2547821 is 1287452.

2547821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2449225 + 98596 = 1565^2 + 314^2 .

It is a cyclic number.

It is not a de Polignac number, because 2547821 - 2² = 2547817 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2540821) 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 as a sum of consecutive naturals, namely, 1273910 + 1273911.

It is an arithmetic number, because the mean of its divisors is an integer number (1273911).

2^2547821 is an apocalyptic number.

It is an amenable number.

2547821 is a deficient number, since it is larger than the sum of its proper divisors (1).

2547821 is an equidigital number, since it uses as much as digits as its factorization.

It is an anagram of its base 9 representation: 2547821 = (4712852)₉.

2547821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 4480, while the sum is 29.

The square root of 2547821 is about 1596.1895250878. The cubic root of 2547821 is about 136.5807954183.

The spelling of 2547821 in words is "two million, five hundred forty-seven thousand, eight hundred twenty-one".