1666723330 has 16 divisors (see below), whose sum is σ = 3056708664. Its totient is φ = 654110080.

The previous prime is 1666723321. The next prime is 1666723343. The reversal of 1666723330 is 333276661.

It can be written as a sum of positive squares in 4 ways, for example, as 1043871481 + 622851849 = 32309^2 + 24957^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 1666723330.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1571851 + ... + 1572910.

Almost surely, 2^1666723330 is an apocalyptic number.

1666723330 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1666723330 is a deficient number, since it is larger than the sum of its proper divisors (1389985334).

1666723330 is a wasteful number, since it uses less digits than its factorization.

1666723330 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3144821.

The product of its (nonzero) digits is 81648, while the sum is 37.

The square root of 1666723330 is about 40825.5230217569. The cubic root of 1666723330 is about 1185.6445377065.

Adding to 1666723330 its reverse (333276661), we get a palindrome (1999999991).

The spelling of 1666723330 in words is "one billion, six hundred sixty-six million, seven hundred twenty-three thousand, three hundred thirty".