21618414373 has 2 divisors, whose sum is σ = 21618414374. Its totient is φ = 21618414372.

The previous prime is 21618414371. The next prime is 21618414397. The reversal of 21618414373 is 37341481612.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 15503487169 + 6114927204 = 124513^2 + 78198^2 .

It is a cyclic number.

It is not a de Polignac number, because 21618414373 - 2¹ = 21618414371 is a prime.

Together with 21618414371, 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 (21618414371) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10809207186 + 10809207187.

It is an arithmetic number, because the mean of its divisors is an integer number (10809207187).

Almost surely, 2^21618414373 is an apocalyptic number.

It is an amenable number.

21618414373 is a deficient number, since it is larger than the sum of its proper divisors (1).

21618414373 is an equidigital number, since it uses as much as digits as its factorization.

21618414373 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 96768, while the sum is 40.

Adding to 21618414373 its reverse (37341481612), we get a palindrome (58959895985).

The spelling of 21618414373 in words is "twenty-one billion, six hundred eighteen million, four hundred fourteen thousand, three hundred seventy-three".