78155077831 has 4 divisors (see below), whose sum is σ = 82268503000. Its totient is φ = 74041652664.

The previous prime is 78155077787. The next prime is 78155077919. The reversal of 78155077831 is 13877055187.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 13877055187 = 3533 ⋅3927839.

It is a cyclic number.

It is not a de Polignac number, because 78155077831 - 2⁷ = 78155077703 is a prime.

It is a super-2 number, since 2×78155077831² (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 (78155077631) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2056712556 + ... + 2056712593.

It is an arithmetic number, because the mean of its divisors is an integer number (20567125750).

Almost surely, 2^78155077831 is an apocalyptic number.

78155077831 is a deficient number, since it is larger than the sum of its proper divisors (4113425169).

78155077831 is a wasteful number, since it uses less digits than its factorization.

78155077831 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4113425168.

The product of its (nonzero) digits is 1646400, while the sum is 52.

The spelling of 78155077831 in words is "seventy-eight billion, one hundred fifty-five million, seventy-seven thousand, eight hundred thirty-one".