1665541766740 has 24 divisors (see below), whose sum is σ = 3506360015592. Its totient is φ = 664555315200.

The previous prime is 1665541766711. The next prime is 1665541766747. The reversal of 1665541766740 is 476671455661.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 296637086736 + 1368904680004 = 544644^2 + 1170002^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1665541766747) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 103828749 + ... + 103844788.

It is an arithmetic number, because the mean of its divisors is an integer number (146098333983).

Almost surely, 2^{1665541766740} is an apocalyptic number.

1665541766740 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1665541766740 is an abundant number, since it is smaller than the sum of its proper divisors (1840818248852).

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

1665541766740 is a wasteful number, since it uses less digits than its factorization.

1665541766740 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 207673947 (or 207673945 counting only the distinct ones).

The product of its (nonzero) digits is 25401600, while the sum is 58.

The spelling of 1665541766740 in words is "one trillion, six hundred sixty-five billion, five hundred forty-one million, seven hundred sixty-six thousand, seven hundred forty".