21213612366731 has 2 divisors, whose sum is σ = 21213612366732. Its totient is φ = 21213612366730.

The previous prime is 21213612366721. The next prime is 21213612366733. The reversal of 21213612366731 is 13766321631212.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 21213612366731 - 2³⁴ = 21196432497547 is a prime.

It is a super-2 number, since 2×21213612366731² (a number of 27 digits) contains 22 as substring.

Together with 21213612366733, it forms a pair of twin primes.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (21213612366733) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10606806183365 + 10606806183366.

It is an arithmetic number, because the mean of its divisors is an integer number (10606806183366).

Almost surely, 2^{21213612366731} is an apocalyptic number.

21213612366731 is a deficient number, since it is larger than the sum of its proper divisors (1).

21213612366731 is an equidigital number, since it uses as much as digits as its factorization.

21213612366731 is an evil number, because the sum of its binary digits is even.

The product of its digits is 326592, while the sum is 44.

Adding to 21213612366731 its reverse (13766321631212), we get a palindrome (34979933997943).

The spelling of 21213612366731 in words is "twenty-one trillion, two hundred thirteen billion, six hundred twelve million, three hundred sixty-six thousand, seven hundred thirty-one".