16602981637421 has 2 divisors, whose sum is σ = 16602981637422. Its totient is φ = 16602981637420.

The previous prime is 16602981637331. The next prime is 16602981637457. The reversal of 16602981637421 is 12473618920661.

It is a happy number.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 15618193344196 + 984788293225 = 3951986^2 + 992365^2 .

It is a cyclic number.

It is not a de Polignac number, because 16602981637421 - 2⁴² = 12204935126317 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16602981637721) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8301490818710 + 8301490818711.

It is an arithmetic number, because the mean of its divisors is an integer number (8301490818711).

Almost surely, 2^{16602981637421} is an apocalyptic number.

It is an amenable number.

16602981637421 is a deficient number, since it is larger than the sum of its proper divisors (1).

16602981637421 is an equidigital number, since it uses as much as digits as its factorization.

16602981637421 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 5225472, while the sum is 56.

The spelling of 16602981637421 in words is "sixteen trillion, six hundred two billion, nine hundred eighty-one million, six hundred thirty-seven thousand, four hundred twenty-one".