1666940928 has 128 divisors (see below), whose sum is σ = 4596887040. Its totient is φ = 536739840.

The previous prime is 1666940921. The next prime is 1666940929. The reversal of 1666940928 is 8290496661.

It is a tau number, because it is divible by the number of its divisors (128).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666940921) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 3047151 + ... + 3047697.

It is an arithmetic number, because the mean of its divisors is an integer number (35913180).

Almost surely, 2^1666940928 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1666940928, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2298443520).

1666940928 is an abundant number, since it is smaller than the sum of its proper divisors (2929946112).

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

1666940928 is an frugal number, since it uses more digits than its factorization.

1666940928 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 611 (or 583 counting only the distinct ones).

The product of its (nonzero) digits is 1119744, while the sum is 51.

The square root of 1666940928 is about 40828.1879098252. The cubic root of 1666940928 is about 1185.6961324831.

The spelling of 1666940928 in words is "one billion, six hundred sixty-six million, nine hundred forty thousand, nine hundred twenty-eight".