1666403442 has 80 divisors (see below), whose sum is σ = 4099135392. Its totient is φ = 501785280.

The previous prime is 1666403437. The next prime is 1666403477. The reversal of 1666403442 is 2443046661.

It is a junction number, because it is equal to n+sod(n) for n = 1666403397 and 1666403406.

It is an unprimeable number.

It is a polite number, since it can be written in 39 ways as a sum of consecutive naturals, for example, 287598 + ... + 293334.

Almost surely, 2^1666403442 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1666403442, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2049567696).

1666403442 is an abundant number, since it is smaller than the sum of its proper divisors (2432731950).

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

1666403442 is a wasteful number, since it uses less digits than its factorization.

1666403442 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5925 (or 5916 counting only the distinct ones).

The product of its (nonzero) digits is 82944, while the sum is 36.

The square root of 1666403442 is about 40821.6050884823. The cubic root of 1666403442 is about 1185.5686807401.

The spelling of 1666403442 in words is "one billion, six hundred sixty-six million, four hundred three thousand, four hundred forty-two".