21988373216629 has 2 divisors, whose sum is σ = 21988373216630. Its totient is φ = 21988373216628.

The previous prime is 21988373216627. The next prime is 21988373216717. The reversal of 21988373216629 is 92661237388912.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 13942584236529 + 8045788980100 = 3733977^2 + 2836510^2 .

It is a cyclic number.

It is not a de Polignac number, because 21988373216629 - 2¹ = 21988373216627 is a prime.

Together with 21988373216627, 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 (21988373216627) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10994186608314 + 10994186608315.

It is an arithmetic number, because the mean of its divisors is an integer number (10994186608315).

Almost surely, 2^{21988373216629} is an apocalyptic number.

It is an amenable number.

21988373216629 is a deficient number, since it is larger than the sum of its proper divisors (1).

21988373216629 is an equidigital number, since it uses as much as digits as its factorization.

21988373216629 is an evil number, because the sum of its binary digits is even.

The product of its digits is 94058496, while the sum is 67.

The spelling of 21988373216629 in words is "twenty-one trillion, nine hundred eighty-eight billion, three hundred seventy-three million, two hundred sixteen thousand, six hundred twenty-nine".