78158745511781 has 16 divisors (see below), whose sum is σ = 87429921179328. Its totient is φ = 69251963932800.

The previous prime is 78158745511747. The next prime is 78158745511831. The reversal of 78158745511781 is 18711554785187.

It is not a de Polignac number, because 78158745511781 - 2¹⁰ = 78158745510757 is a prime.

It is a super-2 number, since 2×78158745511781² (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 (78158745531781) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 85081631 + ... + 85995356.

It is an arithmetic number, because the mean of its divisors is an integer number (5464370073708).

Almost surely, 2^{78158745511781} is an apocalyptic number.

It is an amenable number.

78158745511781 is a deficient number, since it is larger than the sum of its proper divisors (9271175667547).

78158745511781 is a wasteful number, since it uses less digits than its factorization.

78158745511781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 171078052.

The product of its digits is 87808000, while the sum is 68.

The spelling of 78158745511781 in words is "seventy-eight trillion, one hundred fifty-eight billion, seven hundred forty-five million, five hundred eleven thousand, seven hundred eighty-one".