2640857 has 2 divisors, whose sum is σ = 2640858. Its totient is φ = 2640856.

The previous prime is 2640853. The next prime is 2640863. The reversal of 2640857 is 7580462.

2640857 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., 2637376 + 3481 = 1624^2 + 59^2 .

It is a cyclic number.

It is not a de Polignac number, because 2640857 - 2² = 2640853 is a prime.

It is an Ulam number.

It is not a weakly prime, because it can be changed into another prime (2640853) 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, 1320428 + 1320429.

It is an arithmetic number, because the mean of its divisors is an integer number (1320429).

2^2640857 is an apocalyptic number.

It is an amenable number.

2640857 is a deficient number, since it is larger than the sum of its proper divisors (1).

2640857 is an equidigital number, since it uses as much as digits as its factorization.

2640857 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 13440, while the sum is 32.

The square root of 2640857 is about 1625.0713830475. The cubic root of 2640857 is about 138.2234181154.

The spelling of 2640857 in words is "two million, six hundred forty thousand, eight hundred fifty-seven".