85781161731 has 4 divisors (see below), whose sum is σ = 114374882312. Its totient is φ = 57187441152.

The previous prime is 85781161729. The next prime is 85781161757. The reversal of 85781161731 is 13716118758.

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

It is not a de Polignac number, because 85781161731 - 2¹ = 85781161729 is a prime.

It is a super-2 number, since 2×85781161731² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (85781161331) 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, 14296860286 + ... + 14296860291.

It is an arithmetic number, because the mean of its divisors is an integer number (28593720578).

Almost surely, 2^85781161731 is an apocalyptic number.

85781161731 is a deficient number, since it is larger than the sum of its proper divisors (28593720581).

85781161731 is a wasteful number, since it uses less digits than its factorization.

85781161731 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28593720580.

The product of its digits is 282240, while the sum is 48.

The spelling of 85781161731 in words is "eighty-five billion, seven hundred eighty-one million, one hundred sixty-one thousand, seven hundred thirty-one".