1665635578980 has 48 divisors (see below), whose sum is σ = 4824599613120. Its totient is φ = 428853298048.

The previous prime is 1665635578967. The next prime is 1665635578993. The reversal of 1665635578980 is 898755365661.

It is an interprime number because it is at equal distance from previous prime (1665635578967) and next prime (1665635578993).

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 478629174 + ... + 478632653.

It is an arithmetic number, because the mean of its divisors is an integer number (100512491940).

Almost surely, 2^{1665635578980} is an apocalyptic number.

1665635578980 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

1665635578980 is an abundant number, since it is smaller than the sum of its proper divisors (3158964034140).

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

1665635578980 is a wasteful number, since it uses less digits than its factorization.

1665635578980 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 957261868 (or 957261866 counting only the distinct ones).

The product of its (nonzero) digits is 326592000, while the sum is 69.

The spelling of 1665635578980 in words is "one trillion, six hundred sixty-five billion, six hundred thirty-five million, five hundred seventy-eight thousand, nine hundred eighty".