78965664667831 has 4 divisors (see below), whose sum is σ = 78967525484232. Its totient is φ = 78963803851432.

The previous prime is 78965664667829. The next prime is 78965664667871. The reversal of 78965664667831 is 13876646656987.

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 78965664667831 - 2¹ = 78965664667829 is a prime.

It is a super-2 number, since 2×78965664667831² (a number of 29 digits) contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78965664667811) 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, 930344545 + ... + 930429418.

It is an arithmetic number, because the mean of its divisors is an integer number (19741881371058).

Almost surely, 2^{78965664667831} is an apocalyptic number.

78965664667831 is a deficient number, since it is larger than the sum of its proper divisors (1860816401).

78965664667831 is a wasteful number, since it uses less digits than its factorization.

78965664667831 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1860816400.

The product of its digits is 13168189440, while the sum is 82.

The spelling of 78965664667831 in words is "seventy-eight trillion, nine hundred sixty-five billion, six hundred sixty-four million, six hundred sixty-seven thousand, eight hundred thirty-one".