105720371681 has 4 divisors (see below), whose sum is σ = 111939217092. Its totient is φ = 99501526272.

The previous prime is 105720371671. The next prime is 105720371689. The reversal of 105720371681 is 186173027501.

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 33638861281 + 72081510400 = 183409^2 + 268480^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-105720371681 is a prime.

It is a super-2 number, since 2×105720371681² (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 (105720371689) 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, 3109422680 + ... + 3109422713.

It is an arithmetic number, because the mean of its divisors is an integer number (27984804273).

Almost surely, 2^105720371681 is an apocalyptic number.

It is an amenable number.

105720371681 is a deficient number, since it is larger than the sum of its proper divisors (6218845411).

105720371681 is an equidigital number, since it uses as much as digits as its factorization.

105720371681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6218845410.

The product of its (nonzero) digits is 70560, while the sum is 41.

The spelling of 105720371681 in words is "one hundred five billion, seven hundred twenty million, three hundred seventy-one thousand, six hundred eighty-one".