78328584181 has 2 divisors, whose sum is σ = 78328584182. Its totient is φ = 78328584180.

The previous prime is 78328584179. The next prime is 78328584199. The reversal of 78328584181 is 18148582387.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 75537575281 + 2791008900 = 274841^2 + 52830^2 .

It is a cyclic number.

It is not a de Polignac number, because 78328584181 - 2¹ = 78328584179 is a prime.

It is a super-2 number, since 2×78328584181² (a number of 23 digits) contains 22 as substring.

Together with 78328584179, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78328584101) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39164292090 + 39164292091.

It is an arithmetic number, because the mean of its divisors is an integer number (39164292091).

Almost surely, 2^78328584181 is an apocalyptic number.

It is an amenable number.

78328584181 is a deficient number, since it is larger than the sum of its proper divisors (1).

78328584181 is an equidigital number, since it uses as much as digits as its factorization.

78328584181 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3440640, while the sum is 55.

The spelling of 78328584181 in words is "seventy-eight billion, three hundred twenty-eight million, five hundred eighty-four thousand, one hundred eighty-one".