78242439524173 has 2 divisors, whose sum is σ = 78242439524174. Its totient is φ = 78242439524172.

The previous prime is 78242439524153. The next prime is 78242439524239. The reversal of 78242439524173 is 37142593424287.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 76419731618244 + 1822707905929 = 8741838^2 + 1350077^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78242439524173 is a prime.

It is a super-2 number, since 2×78242439524173² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (78242439524143) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39121219762086 + 39121219762087.

It is an arithmetic number, because the mean of its divisors is an integer number (39121219762087).

Almost surely, 2^{78242439524173} is an apocalyptic number.

It is an amenable number.

78242439524173 is a deficient number, since it is larger than the sum of its proper divisors (1).

78242439524173 is an equidigital number, since it uses as much as digits as its factorization.

78242439524173 is an evil number, because the sum of its binary digits is even.

The product of its digits is 81285120, while the sum is 61.

The spelling of 78242439524173 in words is "seventy-eight trillion, two hundred forty-two billion, four hundred thirty-nine million, five hundred twenty-four thousand, one hundred seventy-three".