78121789900839 has 32 divisors (see below), whose sum is σ = 115992209995200. Its totient is φ = 51965902126080.

The previous prime is 78121789900831. The next prime is 78121789900841. The reversal of 78121789900839 is 93800998712187.

It is not a de Polignac number, because 78121789900839 - 2³ = 78121789900831 is a prime.

It is a super-2 number, since 2×78121789900839² (a number of 29 digits) contains 22 as substring.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (78121789900831) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 305981467 + ... + 306236675.

It is an arithmetic number, because the mean of its divisors is an integer number (3624756562350).

Almost surely, 2^{78121789900839} is an apocalyptic number.

78121789900839 is a deficient number, since it is larger than the sum of its proper divisors (37870420094361).

78121789900839 is a wasteful number, since it uses less digits than its factorization.

78121789900839 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 280272 (or 280266 counting only the distinct ones).

The product of its (nonzero) digits is 109734912, while the sum is 72.

The spelling of 78121789900839 in words is "seventy-eight trillion, one hundred twenty-one billion, seven hundred eighty-nine million, nine hundred thousand, eight hundred thirty-nine".