21002112541 has 2 divisors, whose sum is σ = 21002112542. Its totient is φ = 21002112540.

The previous prime is 21002112499. The next prime is 21002112559. The reversal of 21002112541 is 14521120012.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 14401200025 + 6600912516 = 120005^2 + 81246^2 .

It is a cyclic number.

It is not a de Polignac number, because 21002112541 - 2¹³ = 21002104349 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (21002112581) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10501056270 + 10501056271.

It is an arithmetic number, because the mean of its divisors is an integer number (10501056271).

Almost surely, 2^21002112541 is an apocalyptic number.

It is an amenable number.

21002112541 is a deficient number, since it is larger than the sum of its proper divisors (1).

21002112541 is an equidigital number, since it uses as much as digits as its factorization.

21002112541 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 160, while the sum is 19.

Adding to 21002112541 its reverse (14521120012), we get a palindrome (35523232553).

The spelling of 21002112541 in words is "twenty-one billion, two million, one hundred twelve thousand, five hundred forty-one".