1280380508521 has 9 divisors (see below), whose sum is σ = 1296087708279. Its totient is φ = 1264861451136.

The previous prime is 1280380508501. The next prime is 1280380508527. The reversal of 1280380508521 is 1258050830821.

The square root of 1280380508521 is 1131539.

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., 903954085225 + 376426423296 = 950765^2 + 613536^2 .

It is not a de Polignac number, because 1280380508521 - 2⁵ = 1280380508489 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1280380508527) 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, 93910921 + ... + 93924553.

Almost surely, 2^{1280380508521} is an apocalyptic number.

1280380508521 is the 1131539-th square number.

1280380508521 is the 565770-th centered octagonal number.

It is an amenable number.

1280380508521 is a deficient number, since it is larger than the sum of its proper divisors (15707199758).

1280380508521 is an frugal number, since it uses more digits than its factorization.

1280380508521 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 27432 (or 13716 counting only the distinct ones).

The product of its (nonzero) digits is 153600, while the sum is 43.

The spelling of 1280380508521 in words is "one trillion, two hundred eighty billion, three hundred eighty million, five hundred eight thousand, five hundred twenty-one".