16661121079403 has 2 divisors, whose sum is σ = 16661121079404. Its totient is φ = 16661121079402.

The previous prime is 16661121079313. The next prime is 16661121079409. The reversal of 16661121079403 is 30497012116661.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 16661121079403 - 2¹⁴ = 16661121063019 is a prime.

It is not a weakly prime, because it can be changed into another prime (16661121079409) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 8330560539701 + 8330560539702.

It is an arithmetic number, because the mean of its divisors is an integer number (8330560539702).

Almost surely, 2^{16661121079403} is an apocalyptic number.

16661121079403 is a deficient number, since it is larger than the sum of its proper divisors (1).

16661121079403 is an equidigital number, since it uses as much as digits as its factorization.

16661121079403 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 326592, while the sum is 47.

The spelling of 16661121079403 in words is "sixteen trillion, six hundred sixty-one billion, one hundred twenty-one million, seventy-nine thousand, four hundred three".