811505897 has 4 divisors (see below), whose sum is σ = 859241556. Its totient is φ = 763770240.

The previous prime is 811505837. The next prime is 811505899. The reversal of 811505897 is 798505118.

It is a happy number.

811505897 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 672831721 + 138674176 = 25939^2 + 11776^2 .

It is a cyclic number.

It is not a de Polignac number, because 811505897 - 2⁶ = 811505833 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (811505899) 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, 23867804 + ... + 23867837.

It is an arithmetic number, because the mean of its divisors is an integer number (214810389).

Almost surely, 2^811505897 is an apocalyptic number.

It is an amenable number.

811505897 is a deficient number, since it is larger than the sum of its proper divisors (47735659).

811505897 is a wasteful number, since it uses less digits than its factorization.

811505897 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 47735658.

The product of its (nonzero) digits is 100800, while the sum is 44.

The square root of 811505897 is about 28486.9425702373. The cubic root of 811505897 is about 932.7470697327.

The spelling of 811505897 in words is "eight hundred eleven million, five hundred five thousand, eight hundred ninety-seven".