71961983129 has 4 divisors (see below), whose sum is σ = 72270833076. Its totient is φ = 71653133184.

The previous prime is 71961983069. The next prime is 71961983147. The reversal of 71961983129 is 92138916917.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 92138916917 = 773 ⋅119196529.

It can be written as a sum of positive squares in 2 ways, for example, as 51189967504 + 20772015625 = 226252^2 + 144125^2 .

It is a cyclic number.

It is not a de Polignac number, because 71961983129 - 2²⁰ = 71960934553 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71961988129) 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, 154424624 + ... + 154425089.

It is an arithmetic number, because the mean of its divisors is an integer number (18067708269).

Almost surely, 2^71961983129 is an apocalyptic number.

It is an amenable number.

71961983129 is a deficient number, since it is larger than the sum of its proper divisors (308849947).

71961983129 is a wasteful number, since it uses less digits than its factorization.

71961983129 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 308849946.

The product of its digits is 1469664, while the sum is 56.

The spelling of 71961983129 in words is "seventy-one billion, nine hundred sixty-one million, nine hundred eighty-three thousand, one hundred twenty-nine".