71978781683 has 4 divisors (see below), whose sum is σ = 71981590200. Its totient is φ = 71975973168.

The previous prime is 71978781661. The next prime is 71978781691. The reversal of 71978781683 is 38618787917.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 71978781683 - 2¹⁰ = 71978780659 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71978781653) 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, 1365458 + ... + 1417191.

It is an arithmetic number, because the mean of its divisors is an integer number (17995397550).

Almost surely, 2^71978781683 is an apocalyptic number.

71978781683 is a deficient number, since it is larger than the sum of its proper divisors (2808517).

71978781683 is a wasteful number, since it uses less digits than its factorization.

71978781683 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2808516.

The product of its digits is 28449792, while the sum is 65.

The spelling of 71978781683 in words is "seventy-one billion, nine hundred seventy-eight million, seven hundred eighty-one thousand, six hundred eighty-three".