2174639681 has 4 divisors (see below), whose sum is σ = 2183101572. Its totient is φ = 2166177792.

The previous prime is 2174639657. The next prime is 2174639683. The reversal of 2174639681 is 1869364712.

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 2112229681 + 62410000 = 45959^2 + 7900^2 .

It is a cyclic number.

It is not a de Polignac number, because 2174639681 - 2³⁰ = 1100897857 is a prime.

It is a super-2 number, since 2×2174639681² = 9458115484359563522, which contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (2174639683) 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, 4230560 + ... + 4231073.

It is an arithmetic number, because the mean of its divisors is an integer number (545775393).

Almost surely, 2^2174639681 is an apocalyptic number.

It is an amenable number.

2174639681 is a deficient number, since it is larger than the sum of its proper divisors (8461891).

2174639681 is an equidigital number, since it uses as much as digits as its factorization.

2174639681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 8461890.

The product of its digits is 435456, while the sum is 47.

The square root of 2174639681 is about 46633.0320802755. The cubic root of 2174639681 is about 1295.5746332484.

The spelling of 2174639681 in words is "two billion, one hundred seventy-four million, six hundred thirty-nine thousand, six hundred eighty-one".