21002321941 has 2 divisors, whose sum is σ = 21002321942. Its totient is φ = 21002321940.

The previous prime is 21002321939. The next prime is 21002322043. The reversal of 21002321941 is 14912320012.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 19607000625 + 1395321316 = 140025^2 + 37354^2 .

It is a cyclic number.

It is not a de Polignac number, because 21002321941 - 2¹ = 21002321939 is a prime.

Together with 21002321939, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21002321141) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10501160970 + 10501160971.

It is an arithmetic number, because the mean of its divisors is an integer number (10501160971).

Almost surely, 2^21002321941 is an apocalyptic number.

It is an amenable number.

21002321941 is a deficient number, since it is larger than the sum of its proper divisors (1).

21002321941 is an equidigital number, since it uses as much as digits as its factorization.

21002321941 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 864, while the sum is 25.

Adding to 21002321941 its reverse (14912320012), we get a palindrome (35914641953).

The spelling of 21002321941 in words is "twenty-one billion, two million, three hundred twenty-one thousand, nine hundred forty-one".