16721887038643 has 2 divisors, whose sum is σ = 16721887038644. Its totient is φ = 16721887038642.

The previous prime is 16721887038617. The next prime is 16721887038719. The reversal of 16721887038643 is 34683078812761.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 16721887038643 - 2³³ = 16713297104051 is a prime.

It is a super-2 number, since 2×16721887038643² (a number of 27 digits) contains 22 as substring.

It is not a weakly prime, because it can be changed into another prime (16721887098643) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8360943519321 + 8360943519322.

It is an arithmetic number, because the mean of its divisors is an integer number (8360943519322).

Almost surely, 2^{16721887038643} is an apocalyptic number.

16721887038643 is a deficient number, since it is larger than the sum of its proper divisors (1).

16721887038643 is an equidigital number, since it uses as much as digits as its factorization.

16721887038643 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 65028096, while the sum is 64.

The spelling of 16721887038643 in words is "sixteen trillion, seven hundred twenty-one billion, eight hundred eighty-seven million, thirty-eight thousand, six hundred forty-three".