71277905665 has 4 divisors (see below), whose sum is σ = 85533486804. Its totient is φ = 57022324528.

The previous prime is 71277905651. The next prime is 71277905669. The reversal of 71277905665 is 56650977217.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 56650977217 = 29 ⋅1953481973.

It can be written as a sum of positive squares in 2 ways, for example, as 30245731569 + 41032174096 = 173913^2 + 202564^2 .

It is a cyclic number.

It is not a de Polignac number, because 71277905665 - 2¹⁷ = 71277774593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71277905669) 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, 7127790562 + ... + 7127790571.

It is an arithmetic number, because the mean of its divisors is an integer number (21383371701).

Almost surely, 2^71277905665 is an apocalyptic number.

It is an amenable number.

71277905665 is a deficient number, since it is larger than the sum of its proper divisors (14255581139).

71277905665 is a wasteful number, since it uses less digits than its factorization.

71277905665 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14255581138.

The product of its (nonzero) digits is 5556600, while the sum is 55.

The spelling of 71277905665 in words is "seventy-one billion, two hundred seventy-seven million, nine hundred five thousand, six hundred sixty-five".