1666345540 has 48 divisors (see below), whose sum is σ = 3593613744. Its totient is φ = 648806400.

The previous prime is 1666345531. The next prime is 1666345591. The reversal of 1666345540 is 455436661.

It can be written as a sum of positive squares in 8 ways, for example, as 78004224 + 1588341316 = 8832^2 + 39854^2 .

It is a junction number, because it is equal to n+sod(n) for n = 1666345493 and 1666345502.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 111300 + ... + 125380.

It is an arithmetic number, because the mean of its divisors is an integer number (74866953).

Almost surely, 2^1666345540 is an apocalyptic number.

1666345540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1666345540 is an abundant number, since it is smaller than the sum of its proper divisors (1927268204).

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

1666345540 is a wasteful number, since it uses less digits than its factorization.

1666345540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14248 (or 14246 counting only the distinct ones).

The product of its (nonzero) digits is 259200, while the sum is 40.

The square root of 1666345540 is about 40820.8958745395. The cubic root of 1666345540 is about 1185.5549490529.

The spelling of 1666345540 in words is "one billion, six hundred sixty-six million, three hundred forty-five thousand, five hundred forty".