129384809401 has 3 divisors (see below), whose sum is σ = 129385169103. Its totient is φ = 129384449700.

The previous prime is 129384809357. The next prime is 129384809443. The reversal of 129384809401 is 104908483921.

The square root of 129384809401 is 359701.

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

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 104908483921 = 53 ⋅1979405357.

It can be written as a sum of positive squares in only one way, i.e., 128093125801 + 1291683600 = 357901^2 + 35940^2 .

It is not a de Polignac number, because 129384809401 - 2¹³ = 129384801209 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (129384804401) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 179851 + ... + 539551.

It is an arithmetic number, because the mean of its divisors is an integer number (43128389701).

Almost surely, 2^129384809401 is an apocalyptic number.

129384809401 is the 359701-st square number.

129384809401 is the 179851-st centered octagonal number.

It is an amenable number.

129384809401 is a deficient number, since it is larger than the sum of its proper divisors (359702).

129384809401 is an frugal number, since it uses more digits than its factorization.

129384809401 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 719402 (or 359701 counting only the distinct ones).

The product of its (nonzero) digits is 497664, while the sum is 49.

Multiplying 129384809401 by its sum of digits (49), we get a square (6339855660649 = 2517907²).

The spelling of 129384809401 in words is "one hundred twenty-nine billion, three hundred eighty-four million, eight hundred nine thousand, four hundred one".