2145908571665 has 8 divisors (see below), whose sum is σ = 2584663113960. Its totient is φ = 1710344972032.

The previous prime is 2145908571647. The next prime is 2145908571721. The reversal of 2145908571665 is 5661758095412.

It is a Cunningham number, because it is equal to 1464892²+1.

It can be written as a sum of positive squares in 4 ways, for example, as 141189565504 + 2004719006161 = 375752^2 + 1415881^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 2145908571665 - 2²⁶ = 2145841462801 is a prime.

It is a super-3 number, since 3×2145908571665³ (a number of 38 digits) contains 333 as substring.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 797734184 + ... + 797736873.

It is an arithmetic number, because the mean of its divisors is an integer number (323082889245).

Almost surely, 2^{2145908571665} is an apocalyptic number.

It is an amenable number.

2145908571665 is a deficient number, since it is larger than the sum of its proper divisors (438754542295).

2145908571665 is a wasteful number, since it uses less digits than its factorization.

2145908571665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1595471331.

The product of its (nonzero) digits is 18144000, while the sum is 59.

The spelling of 2145908571665 in words is "two trillion, one hundred forty-five billion, nine hundred eight million, five hundred seventy-one thousand, six hundred sixty-five".