812881261 has 2 divisors, whose sum is σ = 812881262. Its totient is φ = 812881260.

The previous prime is 812881259. The next prime is 812881273. The reversal of 812881261 is 162188218.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 570923236 + 241958025 = 23894^2 + 15555^2 .

It is a cyclic number.

It is not a de Polignac number, because 812881261 - 2¹ = 812881259 is a prime.

Together with 812881259, it forms a pair of twin primes.

It is a Chen prime.

It is a self number, because there is not a number n which added to its sum of digits gives 812881261.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (812881361) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 406440630 + 406440631.

It is an arithmetic number, because the mean of its divisors is an integer number (406440631).

Almost surely, 2^812881261 is an apocalyptic number.

It is an amenable number.

812881261 is a deficient number, since it is larger than the sum of its proper divisors (1).

812881261 is an equidigital number, since it uses as much as digits as its factorization.

812881261 is an evil number, because the sum of its binary digits is even.

The product of its digits is 12288, while the sum is 37.

The square root of 812881261 is about 28511.0726034641. The cubic root of 812881261 is about 933.2737213486.

The spelling of 812881261 in words is "eight hundred twelve million, eight hundred eighty-one thousand, two hundred sixty-one".