16843911684221 has 2 divisors, whose sum is σ = 16843911684222. Its totient is φ = 16843911684220.

The previous prime is 16843911684139. The next prime is 16843911684251. The reversal of 16843911684221 is 12248611934861.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 10598605802500 + 6245305881721 = 3255550^2 + 2499061^2 .

It is a cyclic number.

It is not a de Polignac number, because 16843911684221 - 2²² = 16843907489917 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16843911684251) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8421955842110 + 8421955842111.

It is an arithmetic number, because the mean of its divisors is an integer number (8421955842111).

Almost surely, 2^{16843911684221} is an apocalyptic number.

It is an amenable number.

16843911684221 is a deficient number, since it is larger than the sum of its proper divisors (1).

16843911684221 is an equidigital number, since it uses as much as digits as its factorization.

16843911684221 is an evil number, because the sum of its binary digits is even.

The product of its digits is 3981312, while the sum is 56.

The spelling of 16843911684221 in words is "sixteen trillion, eight hundred forty-three billion, nine hundred eleven million, six hundred eighty-four thousand, two hundred twenty-one".