21130354521236 has 6 divisors (see below), whose sum is σ = 36978120412170. Its totient is φ = 10565177260616.

The previous prime is 21130354521217. The next prime is 21130354521247. The reversal of 21130354521236 is 63212545303112.

It can be written as a sum of positive squares in only one way, i.e., 19596115562500 + 1534238958736 = 4426750^2 + 1238644^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 21130354521236.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2641294315151 + ... + 2641294315158.

It is an arithmetic number, because the mean of its divisors is an integer number (6163020068695).

Almost surely, 2^{21130354521236} is an apocalyptic number.

It is an amenable number.

21130354521236 is a deficient number, since it is larger than the sum of its proper divisors (15847765890934).

21130354521236 is a wasteful number, since it uses less digits than its factorization.

21130354521236 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5282588630313 (or 5282588630311 counting only the distinct ones).

The product of its (nonzero) digits is 129600, while the sum is 38.

Adding to 21130354521236 its reverse (63212545303112), we get a palindrome (84342899824348).

The spelling of 21130354521236 in words is "twenty-one trillion, one hundred thirty billion, three hundred fifty-four million, five hundred twenty-one thousand, two hundred thirty-six".