1666953558 has 24 divisors (see below), whose sum is σ = 3612983400. Its totient is φ = 555458784.

The previous prime is 1666953557. The next prime is 1666953571. The reversal of 1666953558 is 8553596661.

It is a happy number.

It is a Smith number, since the sum of its digits (54) coincides with the sum of the digits of its prime factors.

It is a Curzon number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666953551) 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 11 ways as a sum of consecutive naturals, for example, 43333 + ... + 72191.

It is an arithmetic number, because the mean of its divisors is an integer number (150540975).

Almost surely, 2^1666953558 is an apocalyptic number.

1666953558 is a gapful number since it is divisible by the number (18) formed by its first and last digit.

1666953558 is an abundant number, since it is smaller than the sum of its proper divisors (1946029842).

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

1666953558 is a wasteful number, since it uses less digits than its factorization.

1666953558 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32076 (or 32073 counting only the distinct ones).

The product of its digits is 5832000, while the sum is 54.

The square root of 1666953558 is about 40828.3425820838. The cubic root of 1666953558 is about 1185.6991270512.

The spelling of 1666953558 in words is "one billion, six hundred sixty-six million, nine hundred fifty-three thousand, five hundred fifty-eight".