1666590380 has 192 divisors, whose sum is σ = 4503797760. Its totient is φ = 503884800.

The previous prime is 1666590379. The next prime is 1666590391. The reversal of 1666590380 is 830956661.

It is a Smith number, since the sum of its digits (44) coincides with the sum of the digits of its prime factors.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 6149645 + ... + 6149915.

It is an arithmetic number, because the mean of its divisors is an integer number (23457280).

Almost surely, 2^1666590380 is an apocalyptic number.

1666590380 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 1666590380, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2251898880).

1666590380 is an abundant number, since it is smaller than the sum of its proper divisors (2837207380).

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

1666590380 is a wasteful number, since it uses less digits than its factorization.

1666590380 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 440 (or 438 counting only the distinct ones).

The product of its (nonzero) digits is 233280, while the sum is 44.

The square root of 1666590380 is about 40823.8947186571. The cubic root of 1666590380 is about 1185.6130116518.

The spelling of 1666590380 in words is "one billion, six hundred sixty-six million, five hundred ninety thousand, three hundred eighty".