812715289 has 4 divisors (see below), whose sum is σ = 813706020. Its totient is φ = 811724560.

The previous prime is 812715283. The next prime is 812715307. The reversal of 812715289 is 982517218.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 982517218 = 2 ⋅491258609.

It can be written as a sum of positive squares in 2 ways, for example, as 63872064 + 748843225 = 7992^2 + 27365^2 .

It is a cyclic number.

It is not a de Polignac number, because 812715289 - 2¹³ = 812707097 is a prime.

It is a super-2 number, since 2×812715289² = 1321012281948707042, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (812715283) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 494134 + ... + 495775.

It is an arithmetic number, because the mean of its divisors is an integer number (203426505).

Almost surely, 2^812715289 is an apocalyptic number.

It is an amenable number.

812715289 is a deficient number, since it is larger than the sum of its proper divisors (990731).

812715289 is an equidigital number, since it uses as much as digits as its factorization.

812715289 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 990730.

The product of its digits is 80640, while the sum is 43.

The square root of 812715289 is about 28508.1617962295. The cubic root of 812715289 is about 933.2101992177.

The spelling of 812715289 in words is "eight hundred twelve million, seven hundred fifteen thousand, two hundred eighty-nine".