810036781 has 2 divisors, whose sum is σ = 810036782. Its totient is φ = 810036780.

The previous prime is 810036769. The next prime is 810036803. The reversal of 810036781 is 187630018.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 660952681 + 149084100 = 25709^2 + 12210^2 .

It is a cyclic number.

It is not a de Polignac number, because 810036781 - 2⁷ = 810036653 is a prime.

It is a super-2 number, since 2×810036781² = 1312319173145683922, which contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (810036761) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 405018390 + 405018391.

It is an arithmetic number, because the mean of its divisors is an integer number (405018391).

Almost surely, 2^810036781 is an apocalyptic number.

It is an amenable number.

810036781 is a deficient number, since it is larger than the sum of its proper divisors (1).

810036781 is an equidigital number, since it uses as much as digits as its factorization.

810036781 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 34.

The square root of 810036781 is about 28461.1451104835. The cubic root of 810036781 is about 932.1838610934.

Adding to 810036781 its reverse (187630018), we get a palindrome (997666799).

The spelling of 810036781 in words is "eight hundred ten million, thirty-six thousand, seven hundred eighty-one".