129236778864 has 120 divisors (see below), whose sum is σ = 364937610752. Its totient is φ = 42692106240.

The previous prime is 129236778823. The next prime is 129236778877. The reversal of 129236778864 is 468877632921.

129236778864 is a `hidden beast` number, since 129 + 2 + 367 + 78 + 86 + 4 = 666.

It is a super-2 number, since 2×129236778864² (a number of 23 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 18888084 + ... + 18894924.

Almost surely, 2^129236778864 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 129236778864, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (182468805376).

129236778864 is an abundant number, since it is smaller than the sum of its proper divisors (235700831888).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

129236778864 is a wasteful number, since it uses less digits than its factorization.

129236778864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8015 (or 8006 counting only the distinct ones).

The product of its digits is 48771072, while the sum is 63.

The spelling of 129236778864 in words is "one hundred twenty-nine billion, two hundred thirty-six million, seven hundred seventy-eight thousand, eight hundred sixty-four".