1666344960 has 720 divisors, whose sum is σ = 7117290180. Its totient is φ = 371589120.

The previous prime is 1666344931. The next prime is 1666344961. The reversal of 1666344960 is 694436661.

It can be written as a sum of positive squares in 2 ways, for example, as 1467196416 + 199148544 = 38304^2 + 14112^2 .

It is a tau number, because it is divible by the number of its divisors (720).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666344961) by changing a digit.

It is a polite number, since it can be written in 59 ways as a sum of consecutive naturals, for example, 40642540 + ... + 40642580.

Almost surely, 2^1666344960 is an apocalyptic number.

1666344960 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 1666344960, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (3558645090).

1666344960 is an abundant number, since it is smaller than the sum of its proper divisors (5450945220).

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

1666344960 is an equidigital number, since it uses as much as digits as its factorization.

1666344960 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 94 (or 58 counting only the distinct ones).

The product of its (nonzero) digits is 559872, while the sum is 45.

The square root of 1666344960 is about 40820.8887703342. Note that the first 3 decimals coincide. The cubic root of 1666344960 is about 1185.5548115020.

The spelling of 1666344960 in words is "one billion, six hundred sixty-six million, three hundred forty-four thousand, nine hundred sixty".