2689861 has 2 divisors, whose sum is σ = 2689862. Its totient is φ = 2689860.

The previous prime is 2689807. The next prime is 2689867. The reversal of 2689861 is 1689862.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1890625 + 799236 = 1375^2 + 894^2 .

It is a cyclic number.

It is not a de Polignac number, because 2689861 - 2¹¹ = 2687813 is a prime.

It is a nialpdrome in base 12.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2689867) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1344930 + 1344931.

It is an arithmetic number, because the mean of its divisors is an integer number (1344931).

2^2689861 is an apocalyptic number.

It is an amenable number.

2689861 is a deficient number, since it is larger than the sum of its proper divisors (1).

2689861 is an equidigital number, since it uses as much as digits as its factorization.

2689861 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 41472, while the sum is 40.

The square root of 2689861 is about 1640.0795712404. The cubic root of 2689861 is about 139.0731461193.

Subtracting from 2689861 its reverse (1689862), we obtain a palindrome (999999).

The spelling of 2689861 in words is "two million, six hundred eighty-nine thousand, eight hundred sixty-one".