129281236249 has 9 divisors (see below), whose sum is σ = 142106863381. Its totient is φ = 117524801020.

The previous prime is 129281236193. The next prime is 129281236327. The reversal of 129281236249 is 942632182921.

The square root of 129281236249 is 359557.

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

It is not a de Polignac number, because 129281236249 - 2²⁵ = 129247681817 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (129281234249) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 3938784 + ... + 3971470.

Almost surely, 2^129281236249 is an apocalyptic number.

129281236249 is the 359557-th square number.

129281236249 is the 179779-th centered octagonal number.

It is an amenable number.

129281236249 is a deficient number, since it is larger than the sum of its proper divisors (12825627132).

129281236249 is an frugal number, since it uses more digits than its factorization.

129281236249 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 65396 (or 32698 counting only the distinct ones).

The product of its digits is 746496, while the sum is 49.

Multiplying 129281236249 by its sum of digits (49), we get a square (6334780576201 = 2516899²).

The spelling of 129281236249 in words is "one hundred twenty-nine billion, two hundred eighty-one million, two hundred thirty-six thousand, two hundred forty-nine".