21736489361 has 2 divisors, whose sum is σ = 21736489362. Its totient is φ = 21736489360.

The previous prime is 21736489349. The next prime is 21736489363. The reversal of 21736489361 is 16398463712.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 21618114961 + 118374400 = 147031^2 + 10880^2 .

It is a cyclic number.

It is not a de Polignac number, because 21736489361 - 2³⁰ = 20662747537 is a prime.

It is a super-3 number, since 3×21736489361³ (a number of 32 digits) contains 333 as substring.

It is a Sophie Germain prime.

Together with 21736489363, it forms a pair of twin primes.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (21736489363) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10868244680 + 10868244681.

It is an arithmetic number, because the mean of its divisors is an integer number (10868244681).

Almost surely, 2^21736489361 is an apocalyptic number.

It is an amenable number.

21736489361 is a deficient number, since it is larger than the sum of its proper divisors (1).

21736489361 is an equidigital number, since it uses as much as digits as its factorization.

21736489361 is an evil number, because the sum of its binary digits is even.

The product of its digits is 1306368, while the sum is 50.

The spelling of 21736489361 in words is "twenty-one billion, seven hundred thirty-six million, four hundred eighty-nine thousand, three hundred sixty-one".