21211325777 has 8 divisors (see below), whose sum is σ = 21234623592. Its totient is φ = 21188044800.

The previous prime is 21211325753. The next prime is 21211325791. The reversal of 21211325777 is 77752311212.

It can be written as a sum of positive squares in 4 ways, for example, as 2021041936 + 19190283841 = 44956^2 + 138529^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 21211325777 - 2¹⁶ = 21211260241 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 21211325777.

It is not an unprimeable number, because it can be changed into a prime (21211325677) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6134033 + ... + 6137489.

It is an arithmetic number, because the mean of its divisors is an integer number (2654327949).

Almost surely, 2^21211325777 is an apocalyptic number.

It is an amenable number.

21211325777 is a deficient number, since it is larger than the sum of its proper divisors (23297815).

21211325777 is a wasteful number, since it uses less digits than its factorization.

21211325777 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8419.

The product of its digits is 41160, while the sum is 38.

Adding to 21211325777 its reverse (77752311212), we get a palindrome (98963636989).

The spelling of 21211325777 in words is "twenty-one billion, two hundred eleven million, three hundred twenty-five thousand, seven hundred seventy-seven".