1666316321670 has 384 divisors, whose sum is σ = 5440595973120. Its totient is φ = 317816294400.

The previous prime is 1666316321647. The next prime is 1666316321689. The reversal of 1666316321670 is 761236136661.

It is a super-2 number, since 2×1666316321670² (a number of 25 digits) contains 22 as substring.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 191 ways as a sum of consecutive naturals, for example, 59114980 + ... + 59143160.

It is an arithmetic number, because the mean of its divisors is an integer number (14168218680).

Almost surely, 2^{1666316321670} is an apocalyptic number.

1666316321670 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is a practical number, because each smaller number is the sum of distinct divisors of 1666316321670, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2720297986560).

1666316321670 is an abundant number, since it is smaller than the sum of its proper divisors (3774279651450).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1666316321670 is a wasteful number, since it uses less digits than its factorization.

1666316321670 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 28412 (or 28401 counting only the distinct ones).

The product of its (nonzero) digits is 979776, while the sum is 48.

The spelling of 1666316321670 in words is "one trillion, six hundred sixty-six billion, three hundred sixteen million, three hundred twenty-one thousand, six hundred seventy".