21131444371 has 2 divisors, whose sum is σ = 21131444372. Its totient is φ = 21131444370.

The previous prime is 21131444293. The next prime is 21131444401. The reversal of 21131444371 is 17344413112.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21131444371 - 2⁹ = 21131443859 is a prime.

It is not a weakly prime, because it can be changed into another prime (21111444371) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10565722185 + 10565722186.

It is an arithmetic number, because the mean of its divisors is an integer number (10565722186).

Almost surely, 2^21131444371 is an apocalyptic number.

21131444371 is a deficient number, since it is larger than the sum of its proper divisors (1).

21131444371 is an equidigital number, since it uses as much as digits as its factorization.

21131444371 is an evil number, because the sum of its binary digits is even.

The product of its digits is 8064, while the sum is 31.

Adding to 21131444371 its reverse (17344413112), we get a palindrome (38475857483).

The spelling of 21131444371 in words is "twenty-one billion, one hundred thirty-one million, four hundred forty-four thousand, three hundred seventy-one".