77866387671 has 4 divisors (see below), whose sum is σ = 103821850232. Its totient is φ = 51910925112.

The previous prime is 77866387663. The next prime is 77866387673. The reversal of 77866387671 is 17678366877.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 17678366877 = 3 ⋅5892788959.

It is not a de Polignac number, because 77866387671 - 2³ = 77866387663 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (77866387673) 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, 12977731276 + ... + 12977731281.

It is an arithmetic number, because the mean of its divisors is an integer number (25955462558).

Almost surely, 2^77866387671 is an apocalyptic number.

77866387671 is a deficient number, since it is larger than the sum of its proper divisors (25955462561).

77866387671 is a wasteful number, since it uses less digits than its factorization.

77866387671 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 25955462560.

The product of its digits is 99574272, while the sum is 66.

The spelling of 77866387671 in words is "seventy-seven billion, eight hundred sixty-six million, three hundred eighty-seven thousand, six hundred seventy-one".