21299618752801 has 9 divisors (see below), whose sum is σ = 21321567921459. Its totient is φ = 21277692170400.

The previous prime is 21299618752787. The next prime is 21299618752817. The reversal of 21299618752801 is 10825781699212.

The square root of 21299618752801 is 4615151.

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., 3618939327201 + 17680679425600 = 1902351^2 + 4204840^2 .

It is not a de Polignac number, because 21299618752801 - 2⁹ = 21299618752289 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21299618752801.

It is not an unprimeable number, because it can be changed into a prime (21299618752301) 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, 6281218816 + ... + 6281222206.

Almost surely, 2^{21299618752801} is an apocalyptic number.

21299618752801 is the 4615151-st square number.

21299618752801 is the 2307576-th centered octagonal number.

It is an amenable number.

21299618752801 is a deficient number, since it is larger than the sum of its proper divisors (21949168658).

21299618752801 is an frugal number, since it uses more digits than its factorization.

21299618752801 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9504 (or 4752 counting only the distinct ones).

The product of its (nonzero) digits is 8709120, while the sum is 61.

The spelling of 21299618752801 in words is "twenty-one trillion, two hundred ninety-nine billion, six hundred eighteen million, seven hundred fifty-two thousand, eight hundred one".