1666020042 has 64 divisors (see below), whose sum is σ = 3987947520. Its totient is φ = 514047600.

The previous prime is 1666020023. The next prime is 1666020049. The reversal of 1666020042 is 2400206661.

It is a happy number.

1666020042 is digitally balanced in base 4, because in such base it contains all the possibile digits an equal number of times.

It is a Harshad number since it is a multiple of its sum of digits (27).

It is a junction number, because it is equal to n+sod(n) for n = 1666019988 and 1666020015.

It is not an unprimeable number, because it can be changed into a prime (1666020049) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 16867 + ... + 60137.

It is an arithmetic number, because the mean of its divisors is an integer number (62311680).

Almost surely, 2^1666020042 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1666020042, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (1993973760).

1666020042 is an abundant number, since it is smaller than the sum of its proper divisors (2321927478).

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

1666020042 is a wasteful number, since it uses less digits than its factorization.

1666020042 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 43336 (or 43330 counting only the distinct ones).

The product of its (nonzero) digits is 3456, while the sum is 27.

The square root of 1666020042 is about 40816.9087756533. The cubic root of 1666020042 is about 1185.4777499996.

The spelling of 1666020042 in words is "one billion, six hundred sixty-six million, twenty thousand, forty-two".