78152027016521 has 2 divisors, whose sum is σ = 78152027016522. Its totient is φ = 78152027016520.

The previous prime is 78152027016509. The next prime is 78152027016527. The reversal of 78152027016521 is 12561072025187.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 74995790520121 + 3156236496400 = 8660011^2 + 1776580^2 .

It is a cyclic number.

It is not a de Polignac number, because 78152027016521 - 2⁶ = 78152027016457 is a prime.

It is a super-2 number, since 2×78152027016521² (a number of 29 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (78152027016527) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 39076013508260 + 39076013508261.

It is an arithmetic number, because the mean of its divisors is an integer number (39076013508261).

Almost surely, 2^{78152027016521} is an apocalyptic number.

It is an amenable number.

78152027016521 is a deficient number, since it is larger than the sum of its proper divisors (1).

78152027016521 is an equidigital number, since it uses as much as digits as its factorization.

78152027016521 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 470400, while the sum is 47.

The spelling of 78152027016521 in words is "seventy-eight trillion, one hundred fifty-two billion, twenty-seven million, sixteen thousand, five hundred twenty-one".