812265561 has 12 divisors (see below), whose sum is σ = 1235023920. Its totient is φ = 513009720.

The previous prime is 812265557. The next prime is 812265563. The reversal of 812265561 is 165562218.

812265561 is a `hidden beast` number, since 81 + 2 + 26 + 556 + 1 = 666.

It is not a de Polignac number, because 812265561 - 2² = 812265557 is a prime.

It is not an unprimeable number, because it can be changed into a prime (812265563) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2374875 + ... + 2375216.

It is an arithmetic number, because the mean of its divisors is an integer number (102918660).

Almost surely, 2^812265561 is an apocalyptic number.

It is an amenable number.

812265561 is a deficient number, since it is larger than the sum of its proper divisors (422758359).

812265561 is a wasteful number, since it uses less digits than its factorization.

812265561 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4750116 (or 4750113 counting only the distinct ones).

The product of its digits is 28800, while the sum is 36.

The square root of 812265561 is about 28500.2729986925. The cubic root of 812265561 is about 933.0380322445.

The spelling of 812265561 in words is "eight hundred twelve million, two hundred sixty-five thousand, five hundred sixty-one".