77881986965 has 4 divisors (see below), whose sum is σ = 93458384364. Its totient is φ = 62305589568.

The previous prime is 77881986947. The next prime is 77881986983. The reversal of 77881986965 is 56968918877.

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

It is an interprime number because it is at equal distance from previous prime (77881986947) and next prime (77881986983).

It can be written as a sum of positive squares in 2 ways, for example, as 48996265201 + 28885721764 = 221351^2 + 169958^2 .

It is a cyclic number.

It is not a de Polignac number, because 77881986965 - 2¹⁴ = 77881970581 is a prime.

It is a super-2 number, since 2×77881986965² (a number of 23 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 77881986892 and 77881986901.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7788198692 + ... + 7788198701.

It is an arithmetic number, because the mean of its divisors is an integer number (23364596091).

Almost surely, 2^77881986965 is an apocalyptic number.

It is an amenable number.

77881986965 is a deficient number, since it is larger than the sum of its proper divisors (15576397399).

77881986965 is a wasteful number, since it uses less digits than its factorization.

77881986965 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 15576397398.

The product of its digits is 365783040, while the sum is 74.

The spelling of 77881986965 in words is "seventy-seven billion, eight hundred eighty-one million, nine hundred eighty-six thousand, nine hundred sixty-five".