11872169861 has 4 divisors (see below), whose sum is σ = 12570532812. Its totient is φ = 11173806912.

The previous prime is 11872169857. The next prime is 11872169887. The reversal of 11872169861 is 16896127811.

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 7291452100 + 4580717761 = 85390^2 + 67681^2 .

It is a cyclic number.

It is not a de Polignac number, because 11872169861 - 2² = 11872169857 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (11872169891) 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, 349181450 + ... + 349181483.

It is an arithmetic number, because the mean of its divisors is an integer number (3142633203).

Almost surely, 2^11872169861 is an apocalyptic number.

It is an amenable number.

11872169861 is a deficient number, since it is larger than the sum of its proper divisors (698362951).

11872169861 is an equidigital number, since it uses as much as digits as its factorization.

11872169861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 698362950.

The product of its digits is 290304, while the sum is 50.

The spelling of 11872169861 in words is "eleven billion, eight hundred seventy-two million, one hundred sixty-nine thousand, eight hundred sixty-one".