21280754864317 has 4 divisors (see below), whose sum is σ = 22917736007740. Its totient is φ = 19643773720896.

The previous prime is 21280754864297. The next prime is 21280754864353. The reversal of 21280754864317 is 71346845708212.

It is a happy number.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 14128735310041 + 7152019554276 = 3758821^2 + 2674326^2 .

It is not a de Polignac number, because 21280754864317 - 2¹⁵ = 21280754831549 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21280754814317) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 818490571692 + ... + 818490571717.

It is an arithmetic number, because the mean of its divisors is an integer number (5729434001935).

Almost surely, 2^{21280754864317} is an apocalyptic number.

It is an amenable number.

21280754864317 is a deficient number, since it is larger than the sum of its proper divisors (1636981143423).

21280754864317 is a wasteful number, since it uses less digits than its factorization.

21280754864317 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1636981143422.

The product of its (nonzero) digits is 18063360, while the sum is 58.

The spelling of 21280754864317 in words is "twenty-one trillion, two hundred eighty billion, seven hundred fifty-four million, eight hundred sixty-four thousand, three hundred seventeen".