78121789900838 has 16 divisors (see below), whose sum is σ = 122362558295040. Its totient is φ = 37336630860936.

The previous prime is 78121789900831. The next prime is 78121789900841. The reversal of 78121789900838 is 83800998712187.

It is a super-2 number, since 2×78121789900838² (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 polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 590031020 + ... + 590163407.

It is an arithmetic number, because the mean of its divisors is an integer number (7647659893440).

Almost surely, 2^{78121789900838} is an apocalyptic number.

78121789900838 is a deficient number, since it is larger than the sum of its proper divisors (44240768394202).

78121789900838 is a wasteful number, since it uses less digits than its factorization.

78121789900838 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1180195891.

The product of its (nonzero) digits is 97542144, while the sum is 71.

The spelling of 78121789900838 in words is "seventy-eight trillion, one hundred twenty-one billion, seven hundred eighty-nine million, nine hundred thousand, eight hundred thirty-eight".