129821854864 has 105 divisors (see below), whose sum is σ = 279298873759. Its totient is φ = 58456369920.

The previous prime is 129821854847. The next prime is 129821854867. The reversal of 129821854864 is 468458128921.

It is a happy number.

The square root of 129821854864 is 360308.

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

It can be written as a sum of positive squares in 10 ways, for example, as 3507008400 + 126314846464 = 59220^2 + 355408^2 .

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 129821854799 and 129821854808.

It is not an unprimeable number, because it can be changed into a prime (129821854867) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 20 ways as a sum of consecutive naturals, for example, 3166386684 + ... + 3166386724.

Almost surely, 2^129821854864 is an apocalyptic number.

129821854864 is the 360308-th square number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 129821854864

129821854864 is an abundant number, since it is smaller than the sum of its proper divisors (149477018895).

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

129821854864 is an frugal number, since it uses more digits than its factorization.

129821854864 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 168 (or 56 counting only the distinct ones).

The product of its digits is 8847360, while the sum is 58.

The spelling of 129821854864 in words is "one hundred twenty-nine billion, eight hundred twenty-one million, eight hundred fifty-four thousand, eight hundred sixty-four".