811773359261 has 4 divisors (see below), whose sum is σ = 811777779900. Its totient is φ = 811768938624.

The previous prime is 811773359237. The next prime is 811773359291. The reversal of 811773359261 is 162953377118.

It is a happy number.

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 18524843236 + 793248516025 = 136106^2 + 890645^2 .

It is a cyclic number.

It is not a de Polignac number, because 811773359261 - 2⁶ = 811773359197 is a prime.

It is a super-2 number, since 2×811773359261² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (811773359291) 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, 1922366 + ... + 2306303.

It is an arithmetic number, because the mean of its divisors is an integer number (202944444975).

Almost surely, 2^811773359261 is an apocalyptic number.

It is an amenable number.

811773359261 is a deficient number, since it is larger than the sum of its proper divisors (4420639).

811773359261 is a wasteful number, since it uses less digits than its factorization.

811773359261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4420638.

The product of its digits is 1905120, while the sum is 53.

The spelling of 811773359261 in words is "eight hundred eleven billion, seven hundred seventy-three million, three hundred fifty-nine thousand, two hundred sixty-one".