16556021543407 has 2 divisors, whose sum is σ = 16556021543408. Its totient is φ = 16556021543406.

The previous prime is 16556021543359. The next prime is 16556021543441. The reversal of 16556021543407 is 70434512065561.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 16556021543407 - 2¹⁹ = 16556021019119 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (16556021543497) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8278010771703 + 8278010771704.

It is an arithmetic number, because the mean of its divisors is an integer number (8278010771704).

Almost surely, 2^{16556021543407} is an apocalyptic number.

16556021543407 is a deficient number, since it is larger than the sum of its proper divisors (1).

16556021543407 is an equidigital number, since it uses as much as digits as its factorization.

16556021543407 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 3024000, while the sum is 49.

The spelling of 16556021543407 in words is "sixteen trillion, five hundred fifty-six billion, twenty-one million, five hundred forty-three thousand, four hundred seven".