71766607681 has 4 divisors (see below), whose sum is σ = 71769286192. Its totient is φ = 71763929172.

The previous prime is 71766607667. The next prime is 71766607687. The reversal of 71766607681 is 18670666717.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-71766607681 is a prime.

It is a super-2 number, since 2×71766607681² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (71766607687) 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, 1298655 + ... + 1352788.

It is an arithmetic number, because the mean of its divisors is an integer number (17942321548).

Almost surely, 2^71766607681 is an apocalyptic number.

It is an amenable number.

71766607681 is a deficient number, since it is larger than the sum of its proper divisors (2678511).

71766607681 is a wasteful number, since it uses less digits than its factorization.

71766607681 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2678510.

The product of its (nonzero) digits is 3556224, while the sum is 55.

The spelling of 71766607681 in words is "seventy-one billion, seven hundred sixty-six million, six hundred seven thousand, six hundred eighty-one".