1665349557 has 4 divisors (see below), whose sum is σ = 2220466080. Its totient is φ = 1110233036.

The previous prime is 1665349549. The next prime is 1665349561. The reversal of 1665349557 is 7559435661.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1665349557 - 2³ = 1665349549 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1665349057) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 277558257 + ... + 277558262.

It is an arithmetic number, because the mean of its divisors is an integer number (555116520).

Almost surely, 2^1665349557 is an apocalyptic number.

It is an amenable number.

1665349557 is a deficient number, since it is larger than the sum of its proper divisors (555116523).

1665349557 is an equidigital number, since it uses as much as digits as its factorization.

1665349557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 555116522.

The product of its digits is 3402000, while the sum is 51.

The square root of 1665349557 is about 40808.6946250428. The cubic root of 1665349557 is about 1185.3186979513.

The spelling of 1665349557 in words is "one billion, six hundred sixty-five million, three hundred forty-nine thousand, five hundred fifty-seven".