1666515446121 has 8 divisors (see below), whose sum is σ = 2223575548480. Its totient is φ = 1110232820592.

The previous prime is 1666515446093. The next prime is 1666515446129. The reversal of 1666515446121 is 1216445156661.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1666515446121 - 2²⁵ = 1666481891689 is a prime.

It is a super-3 number, since 3×1666515446121³ (a number of 38 digits) contains 333 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1666515446129) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 194364205 + ... + 194372778.

It is an arithmetic number, because the mean of its divisors is an integer number (277946943560).

Almost surely, 2^{1666515446121} is an apocalyptic number.

It is an amenable number.

1666515446121 is a deficient number, since it is larger than the sum of its proper divisors (557060102359).

1666515446121 is a wasteful number, since it uses less digits than its factorization.

1666515446121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 388738415.

The product of its digits is 1036800, while the sum is 48.

The spelling of 1666515446121 in words is "one trillion, six hundred sixty-six billion, five hundred fifteen million, four hundred forty-six thousand, one hundred twenty-one".