105640681 has 4 divisors (see below), whose sum is σ = 105668164. Its totient is φ = 105613200.

The previous prime is 105640651. The next prime is 105640699. The reversal of 105640681 is 186046501.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 186046501 = 79 ⋅2355019.

It can be written as a sum of positive squares in 2 ways, for example, as 73616400 + 32024281 = 8580^2 + 5659^2 .

It is a cyclic number.

It is not a de Polignac number, because 105640681 - 2¹¹ = 105638633 is a prime.

It is a super-2 number, since 2×105640681² = 22319906964287522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (105640651) 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, 6810 + ... + 16051.

It is an arithmetic number, because the mean of its divisors is an integer number (26417041).

Almost surely, 2^105640681 is an apocalyptic number.

It is an amenable number.

105640681 is a deficient number, since it is larger than the sum of its proper divisors (27483).

105640681 is an equidigital number, since it uses as much as digits as its factorization.

105640681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27482.

The product of its (nonzero) digits is 5760, while the sum is 31.

The square root of 105640681 is about 10278.1652545578. The cubic root of 105640681 is about 472.7269885365.

The spelling of 105640681 in words is "one hundred five million, six hundred forty thousand, six hundred eighty-one".