78343631791 has 4 divisors (see below), whose sum is σ = 78344198784. Its totient is φ = 78343064800.

The previous prime is 78343631789. The next prime is 78343631797. The reversal of 78343631791 is 19713634387.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 78343631791 - 2¹ = 78343631789 is a prime.

It is a super-2 number, since 2×78343631791² (a number of 23 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 (78343631797) 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, 74226 + ... + 402736.

It is an arithmetic number, because the mean of its divisors is an integer number (19586049696).

Almost surely, 2^78343631791 is an apocalyptic number.

78343631791 is a deficient number, since it is larger than the sum of its proper divisors (566993).

78343631791 is a wasteful number, since it uses less digits than its factorization.

78343631791 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 566992.

The product of its digits is 2286144, while the sum is 52.

The spelling of 78343631791 in words is "seventy-eight billion, three hundred forty-three million, six hundred thirty-one thousand, seven hundred ninety-one".