1666281456 has 300 divisors, whose sum is σ = 5909625480. Its totient is φ = 450696960.

The previous prime is 1666281443. The next prime is 1666281457. The reversal of 1666281456 is 6541826661.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666281457) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 1205886 + ... + 1207266.

Almost surely, 2^1666281456 is an apocalyptic number.

1666281456 is a gapful number since it is divisible by the number (16) 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 1666281456, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2954812740).

1666281456 is an abundant number, since it is smaller than the sum of its proper divisors (4243344024).

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

1666281456 is a wasteful number, since it uses less digits than its factorization.

1666281456 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1434 (or 1412 counting only the distinct ones).

The product of its digits is 414720, while the sum is 45.

The square root of 1666281456 is about 40820.1109258659. The cubic root of 1666281456 is about 1185.5397509091.

The spelling of 1666281456 in words is "one billion, six hundred sixty-six million, two hundred eighty-one thousand, four hundred fifty-six".