2857020821 has 2 divisors, whose sum is σ = 2857020822. Its totient is φ = 2857020820.

The previous prime is 2857020787. The next prime is 2857020839. The reversal of 2857020821 is 1280207582.

2857020821 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2810590225 + 46430596 = 53015^2 + 6814^2 .

It is a cyclic number.

It is not a de Polignac number, because 2857020821 - 2⁶ = 2857020757 is a prime.

It is a Sophie Germain prime.

It is a Curzon number.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2857020841) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1428510410 + 1428510411.

It is an arithmetic number, because the mean of its divisors is an integer number (1428510411).

Almost surely, 2^2857020821 is an apocalyptic number.

It is an amenable number.

2857020821 is a deficient number, since it is larger than the sum of its proper divisors (1).

2857020821 is an equidigital number, since it uses as much as digits as its factorization.

2857020821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 17920, while the sum is 35.

The square root of 2857020821 is about 53451.1068267066. The cubic root of 2857020821 is about 1418.9632088355.

The spelling of 2857020821 in words is "two billion, eight hundred fifty-seven million, twenty thousand, eight hundred twenty-one".