16661120557403 has 32 divisors (see below), whose sum is σ = 19562490178560. Its totient is φ = 13892101655040.

The previous prime is 16661120557313. The next prime is 16661120557429. The reversal of 16661120557403 is 30475502116661.

It is a happy number.

It is not a de Polignac number, because 16661120557403 - 2¹⁴ = 16661120541019 is a prime.

It is not an unprimeable number, because it can be changed into a prime (16661120557603) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 443013626 + ... + 443051232.

It is an arithmetic number, because the mean of its divisors is an integer number (611327818080).

Almost surely, 2^{16661120557403} is an apocalyptic number.

16661120557403 is a deficient number, since it is larger than the sum of its proper divisors (2901369621157).

16661120557403 is a wasteful number, since it uses less digits than its factorization.

16661120557403 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 42107.

The product of its (nonzero) digits is 907200, while the sum is 47.

The spelling of 16661120557403 in words is "sixteen trillion, six hundred sixty-one billion, one hundred twenty million, five hundred fifty-seven thousand, four hundred three".