16438880621 has 2 divisors, whose sum is σ = 16438880622. Its totient is φ = 16438880620.

The previous prime is 16438880611. The next prime is 16438880629. The reversal of 16438880621 is 12608883461.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 16176278596 + 262602025 = 127186^2 + 16205^2 .

It is an emirp because it is prime and its reverse (12608883461) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 16438880621 - 2¹⁴ = 16438864237 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16438880629) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8219440310 + 8219440311.

It is an arithmetic number, because the mean of its divisors is an integer number (8219440311).

Almost surely, 2^16438880621 is an apocalyptic number.

It is an amenable number.

16438880621 is a deficient number, since it is larger than the sum of its proper divisors (1).

16438880621 is an equidigital number, since it uses as much as digits as its factorization.

16438880621 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 442368, while the sum is 47.

The spelling of 16438880621 in words is "sixteen billion, four hundred thirty-eight million, eight hundred eighty thousand, six hundred twenty-one".