16756456243421 has 2 divisors, whose sum is σ = 16756456243422. Its totient is φ = 16756456243420.

The previous prime is 16756456243411. The next prime is 16756456243427. The reversal of 16756456243421 is 12434265465761.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 12297120225625 + 4459336017796 = 3506725^2 + 2111714^2 .

It is an emirp because it is prime and its reverse (12434265465761) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 16756456243421 - 2¹⁸ = 16756455981277 is a prime.

It is a super-2 number, since 2×16756456243421² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16756456243427) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8378228121710 + 8378228121711.

It is an arithmetic number, because the mean of its divisors is an integer number (8378228121711).

Almost surely, 2^{16756456243421} is an apocalyptic number.

It is an amenable number.

16756456243421 is a deficient number, since it is larger than the sum of its proper divisors (1).

16756456243421 is an equidigital number, since it uses as much as digits as its factorization.

16756456243421 is an evil number, because the sum of its binary digits is even.

The product of its digits is 29030400, while the sum is 56.

The spelling of 16756456243421 in words is "sixteen trillion, seven hundred fifty-six billion, four hundred fifty-six million, two hundred forty-three thousand, four hundred twenty-one".