1665560388 has 12 divisors (see below), whose sum is σ = 3886307600. Its totient is φ = 555186792.

The previous prime is 1665560381. The next prime is 1665560389. The reversal of 1665560388 is 8830655661.

It is a tau number, because it is divible by the number of its divisors (12).

It is not an unprimeable number, because it can be changed into a prime (1665560381) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 69398338 + ... + 69398361.

Almost surely, 2^1665560388 is an apocalyptic number.

It is an amenable number.

1665560388 is an abundant number, since it is smaller than the sum of its proper divisors (2220747212).

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

1665560388 is a wasteful number, since it uses less digits than its factorization.

1665560388 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 138796706 (or 138796704 counting only the distinct ones).

The product of its (nonzero) digits is 1036800, while the sum is 48.

The square root of 1665560388 is about 40811.2777060459. The cubic root of 1665560388 is about 1185.3687157549.

The spelling of 1665560388 in words is "one billion, six hundred sixty-five million, five hundred sixty thousand, three hundred eighty-eight".