1666737540 has 192 divisors, whose sum is σ = 5613753600. Its totient is φ = 408112128.

The previous prime is 1666737529. The next prime is 1666737559. The reversal of 1666737540 is 457376661.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 1635151 + ... + 1636169.

It is an arithmetic number, because the mean of its divisors is an integer number (29238300).

Almost surely, 2^1666737540 is an apocalyptic number.

1666737540 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 1666737540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (2806876800).

1666737540 is an abundant number, since it is smaller than the sum of its proper divisors (3947016060).

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

1666737540 is a wasteful number, since it uses less digits than its factorization.

1666737540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1283 (or 1275 counting only the distinct ones).

The product of its (nonzero) digits is 635040, while the sum is 45.

The square root of 1666737540 is about 40825.6970546738. The cubic root of 1666737540 is about 1185.6479071841.

The spelling of 1666737540 in words is "one billion, six hundred sixty-six million, seven hundred thirty-seven thousand, five hundred forty".