21510967573 has 2 divisors, whose sum is σ = 21510967574. Its totient is φ = 21510967572.

The previous prime is 21510967571. The next prime is 21510967619. The reversal of 21510967573 is 37576901512.

It is a happy number.

It is an a-pointer prime, because the next prime (21510967619) can be obtained adding 21510967573 to its sum of digits (46).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 21480419844 + 30547729 = 146562^2 + 5527^2 .

It is a cyclic number.

It is not a de Polignac number, because 21510967573 - 2¹ = 21510967571 is a prime.

Together with 21510967571, 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 (21510967571) 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, 10755483786 + 10755483787.

It is an arithmetic number, because the mean of its divisors is an integer number (10755483787).

Almost surely, 2^21510967573 is an apocalyptic number.

It is an amenable number.

21510967573 is a deficient number, since it is larger than the sum of its proper divisors (1).

21510967573 is an equidigital number, since it uses as much as digits as its factorization.

21510967573 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 396900, while the sum is 46.

The spelling of 21510967573 in words is "twenty-one billion, five hundred ten million, nine hundred sixty-seven thousand, five hundred seventy-three".