128768298649 has 9 divisors (see below), whose sum is σ = 129415649247. Its totient is φ = 128124175464.

The previous prime is 128768298641. The next prime is 128768298653. The reversal of 128768298649 is 946892867821.

The square root of 128768298649 is 358843.

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., 119928538249 + 8839760400 = 346307^2 + 94020^2 .

It is not a de Polignac number, because 128768298649 - 2³ = 128768298641 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (128768298641) 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, 82174264 + ... + 82175830.

It is an arithmetic number, because the mean of its divisors is an integer number (14379516583).

Almost surely, 2^128768298649 is an apocalyptic number.

128768298649 is the 358843-rd square number.

128768298649 is the 179422-nd centered octagonal number.

It is an amenable number.

128768298649 is a deficient number, since it is larger than the sum of its proper divisors (647350598).

128768298649 is an frugal number, since it uses more digits than its factorization.

128768298649 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3592 (or 1796 counting only the distinct ones).

The product of its digits is 167215104, while the sum is 70.

The spelling of 128768298649 in words is "one hundred twenty-eight billion, seven hundred sixty-eight million, two hundred ninety-eight thousand, six hundred forty-nine".