1666327740 has 384 divisors, whose sum is σ = 6286049280. Its totient is φ = 319334400.

The previous prime is 1666327673. The next prime is 1666327753. The reversal of 1666327740 is 477236661.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a junction number, because it is equal to n+sod(n) for n = 1666327692 and 1666327701.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 127 ways as a sum of consecutive naturals, for example, 3598749 + ... + 3599211.

It is an arithmetic number, because the mean of its divisors is an integer number (16369920).

Almost surely, 2^1666327740 is an apocalyptic number.

1666327740 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1666327740, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3143024640).

1666327740 is an abundant number, since it is smaller than the sum of its proper divisors (4619721540).

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

1666327740 is a wasteful number, since it uses less digits than its factorization.

1666327740 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 553 (or 551 counting only the distinct ones).

The product of its (nonzero) digits is 254016, while the sum is 42.

The square root of 1666327740 is about 40820.6778483650. The cubic root of 1666327740 is about 1185.5507276488.

The spelling of 1666327740 in words is "one billion, six hundred sixty-six million, three hundred twenty-seven thousand, seven hundred forty".