129728191684 has 81 divisors (see below), whose sum is σ = 286111346157. Its totient is φ = 51295110048.

The previous prime is 129728191669. The next prime is 129728191693. The reversal of 129728191684 is 486191827921.

The square root of 129728191684 is 360178.

It is a perfect power (a square), and thus also a powerful number.

It can be written as a sum of positive squares in only one way, i.e., 19190560900 + 110537630784 = 138530^2 + 332472^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 65551407 + ... + 65553385.

Almost surely, 2^129728191684 is an apocalyptic number.

129728191684 is a gapful number since it is divisible by the number (14) formed by its first and last digit.

129728191684 is the 360178-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 129728191684

129728191684 is an abundant number, since it is smaller than the sum of its proper divisors (156383154473).

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

129728191684 is an equidigital number, since it uses as much as digits as its factorization.

129728191684 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4002 (or 2001 counting only the distinct ones).

The product of its digits is 3483648, while the sum is 58.

The spelling of 129728191684 in words is "one hundred twenty-nine billion, seven hundred twenty-eight million, one hundred ninety-one thousand, six hundred eighty-four".