129988486778 has 4 divisors (see below), whose sum is σ = 194982730170. Its totient is φ = 64994243388.

The previous prime is 129988486759. The next prime is 129988486807. The reversal of 129988486778 is 877684889921.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 75593653249 + 54394833529 = 274943^2 + 233227^2 .

It is a junction number, because it is equal to n+sod(n) for n = 129988486699 and 129988486708.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 32497121693 + ... + 32497121696.

Almost surely, 2^129988486778 is an apocalyptic number.

129988486778 is a deficient number, since it is larger than the sum of its proper divisors (64994243392).

129988486778 is an equidigital number, since it uses as much as digits as its factorization.

129988486778 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64994243391.

The product of its digits is 780337152, while the sum is 77.

The spelling of 129988486778 in words is "one hundred twenty-nine billion, nine hundred eighty-eight million, four hundred eighty-six thousand, seven hundred seventy-eight".