1660640165 has 8 divisors (see below), whose sum is σ = 1996132248. Its totient is φ = 1326269440.

The previous prime is 1660640161. The next prime is 1660640173. The reversal of 1660640165 is 5610460661.

It can be written as a sum of positive squares in 4 ways, for example, as 46689889 + 1613950276 = 6833^2 + 40174^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1660640165 - 2² = 1660640161 is a prime.

It is a super-2 number, since 2×1660640165² = 5515451515222454450, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1660640161) 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, 277076 + ... + 283005.

It is an arithmetic number, because the mean of its divisors is an integer number (249516531).

Almost surely, 2^1660640165 is an apocalyptic number.

It is an amenable number.

1660640165 is a deficient number, since it is larger than the sum of its proper divisors (335492083).

1660640165 is an equidigital number, since it uses as much as digits as its factorization.

1660640165 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 560679.

The product of its (nonzero) digits is 25920, while the sum is 35.

The square root of 1660640165 is about 40750.9529336432. The cubic root of 1660640165 is about 1184.2003340421.

The spelling of 1660640165 in words is "one billion, six hundred sixty million, six hundred forty thousand, one hundred sixty-five".