2567821 has 2 divisors, whose sum is σ = 2567822. Its totient is φ = 2567820.

The previous prime is 2567819. The next prime is 2567827. The reversal of 2567821 is 1287652.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 2292196 + 275625 = 1514^2 + 525^2 .

It is a cyclic number.

It is not a de Polignac number, because 2567821 - 2¹ = 2567819 is a prime.

Together with 2567819, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2567827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1283910 + 1283911.

It is an arithmetic number, because the mean of its divisors is an integer number (1283911).

2^2567821 is an apocalyptic number.

It is an amenable number.

2567821 is a deficient number, since it is larger than the sum of its proper divisors (1).

2567821 is an equidigital number, since it uses as much as digits as its factorization.

2567821 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6720, while the sum is 31.

The square root of 2567821 is about 1602.4421986456. The cubic root of 2567821 is about 136.9372437101.

The spelling of 2567821 in words is "two million, five hundred sixty-seven thousand, eight hundred twenty-one".