78111552029557 has 2 divisors, whose sum is σ = 78111552029558. Its totient is φ = 78111552029556.

The previous prime is 78111552029473. The next prime is 78111552029629. The reversal of 78111552029557 is 75592025511187.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 78111552029476 + 81 = 8838074^2 + 9^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-78111552029557 is a prime.

It is a super-2 number, since 2×78111552029557² (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 (78111552029057) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39055776014778 + 39055776014779.

It is an arithmetic number, because the mean of its divisors is an integer number (39055776014779).

Almost surely, 2^{78111552029557} is an apocalyptic number.

It is an amenable number.

78111552029557 is a deficient number, since it is larger than the sum of its proper divisors (1).

78111552029557 is an equidigital number, since it uses as much as digits as its factorization.

78111552029557 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 8820000, while the sum is 58.

The spelling of 78111552029557 in words is "seventy-eight trillion, one hundred eleven billion, five hundred fifty-two million, twenty-nine thousand, five hundred fifty-seven".