861528491273 has 4 divisors (see below), whose sum is σ = 862340489028. Its totient is φ = 860716493520.

The previous prime is 861528491269. The next prime is 861528491279. The reversal of 861528491273 is 372194825168.

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 622121830009 + 239406661264 = 788747^2 + 489292^2 .

It is a cyclic number.

It is not a de Polignac number, because 861528491273 - 2² = 861528491269 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (861528491279) 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, 405997286 + ... + 405999407.

It is an arithmetic number, because the mean of its divisors is an integer number (215585122257).

Almost surely, 2^861528491273 is an apocalyptic number.

It is an amenable number.

861528491273 is a deficient number, since it is larger than the sum of its proper divisors (811997755).

861528491273 is a wasteful number, since it uses less digits than its factorization.

861528491273 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 811997754.

The product of its digits is 5806080, while the sum is 56.

The spelling of 861528491273 in words is "eight hundred sixty-one billion, five hundred twenty-eight million, four hundred ninety-one thousand, two hundred seventy-three".