21487100441 has 2 divisors, whose sum is σ = 21487100442. Its totient is φ = 21487100440.

The previous prime is 21487100419. The next prime is 21487100491. The reversal of 21487100441 is 14400178412.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21256182025 + 230918416 = 145795^2 + 15196^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21487100441 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21487100398 and 21487100407.

It is not a weakly prime, because it can be changed into another prime (21487100491) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10743550220 + 10743550221.

It is an arithmetic number, because the mean of its divisors is an integer number (10743550221).

Almost surely, 2^21487100441 is an apocalyptic number.

It is an amenable number.

21487100441 is a deficient number, since it is larger than the sum of its proper divisors (1).

21487100441 is an equidigital number, since it uses as much as digits as its factorization.

21487100441 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 7168, while the sum is 32.

Adding to 21487100441 its reverse (14400178412), we get a palindrome (35887278853).

The spelling of 21487100441 in words is "twenty-one billion, four hundred eighty-seven million, one hundred thousand, four hundred forty-one".