78990111109987 has 32 divisors (see below), whose sum is σ = 100897806449664. Its totient is φ = 60058217318400.

The previous prime is 78990111109979. The next prime is 78990111110003.

78990111109987 is nontrivially palindromic in base 10.

It is not a de Polignac number, because 78990111109987 - 2³ = 78990111109979 is a prime.

It is a super-2 number, since 2×78990111109987² (a number of 29 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (78990111101987) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 73946658 + ... + 75007255.

It is an arithmetic number, because the mean of its divisors is an integer number (3153056451552).

Almost surely, 2^{78990111109987} is an apocalyptic number.

78990111109987 is a gapful number since it is divisible by the number (77) formed by its first and last digit.

78990111109987 is a deficient number, since it is larger than the sum of its proper divisors (21907695339677).

78990111109987 is a wasteful number, since it uses less digits than its factorization.

78990111109987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 148954099.

The product of its (nonzero) digits is 20575296, while the sum is 70.

The spelling of 78990111109987 in words is "seventy-eight trillion, nine hundred ninety billion, one hundred eleven million, one hundred nine thousand, nine hundred eighty-seven".