809623261 has 2 divisors, whose sum is σ = 809623262. Its totient is φ = 809623260.

The previous prime is 809623259. The next prime is 809623273. The reversal of 809623261 is 162326908.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 806219236 + 3404025 = 28394^2 + 1845^2 .

It is a cyclic number.

It is not a de Polignac number, because 809623261 - 2¹ = 809623259 is a prime.

Together with 809623259, 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 809623261.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (809623201) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 404811630 + 404811631.

It is an arithmetic number, because the mean of its divisors is an integer number (404811631).

Almost surely, 2^809623261 is an apocalyptic number.

It is an amenable number.

809623261 is a deficient number, since it is larger than the sum of its proper divisors (1).

809623261 is an equidigital number, since it uses as much as digits as its factorization.

809623261 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 31104, while the sum is 37.

The square root of 809623261 is about 28453.8795421644. The cubic root of 809623261 is about 932.0252089217.

The spelling of 809623261 in words is "eight hundred nine million, six hundred twenty-three thousand, two hundred sixty-one".