2089781 has 2 divisors, whose sum is σ = 2089782. Its totient is φ = 2089780.

The previous prime is 2089751. The next prime is 2089807. The reversal of 2089781 is 1879802.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 1464100 + 625681 = 1210^2 + 791^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2089781 is a prime.

It is a super-2 number, since 2×2089781² = 8734369255922, which contains 22 as substring.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2089751) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1044890 + 1044891.

It is an arithmetic number, because the mean of its divisors is an integer number (1044891).

2^2089781 is an apocalyptic number.

It is an amenable number.

2089781 is a deficient number, since it is larger than the sum of its proper divisors (1).

2089781 is an equidigital number, since it uses as much as digits as its factorization.

2089781 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8064, while the sum is 35.

The square root of 2089781 is about 1445.6074847620. The cubic root of 2089781 is about 127.8498605818.

The spelling of 2089781 in words is "two million, eighty-nine thousand, seven hundred eighty-one".