2851861 has 2 divisors, whose sum is σ = 2851862. Its totient is φ = 2851860.

The previous prime is 2851853. The next prime is 2851867. The reversal of 2851861 is 1681582.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 2528100 + 323761 = 1590^2 + 569^2 .

It is a cyclic number.

It is not a de Polignac number, because 2851861 - 2³ = 2851853 is a prime.

It is a super-2 number, since 2×2851861² = 16266222326642, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2851867) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1425930 + 1425931.

It is an arithmetic number, because the mean of its divisors is an integer number (1425931).

2^2851861 is an apocalyptic number.

It is an amenable number.

2851861 is a deficient number, since it is larger than the sum of its proper divisors (1).

2851861 is an equidigital number, since it uses as much as digits as its factorization.

2851861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 3840, while the sum is 31.

The square root of 2851861 is about 1688.7453922957. The cubic root of 2851861 is about 141.8108471368.

The spelling of 2851861 in words is "two million, eight hundred fifty-one thousand, eight hundred sixty-one".