1665964018 has 4 divisors (see below), whose sum is σ = 2498946030. Its totient is φ = 832982008.

The previous prime is 1665964009. The next prime is 1665964049. The reversal of 1665964018 is 8104695661.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 8104695661 = 25541 ⋅317321.

It can be written as a sum of positive squares in only one way, i.e., 1489419649 + 176544369 = 38593^2 + 13287^2 .

It is a super-2 number, since 2×1665964018² = 5550872218541408648, which contains 22 as substring.

It is an unprimeable number.

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 as a sum of consecutive naturals, namely, 416491003 + ... + 416491006.

Almost surely, 2^1665964018 is an apocalyptic number.

1665964018 is a deficient number, since it is larger than the sum of its proper divisors (832982012).

1665964018 is an equidigital number, since it uses as much as digits as its factorization.

1665964018 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 832982011.

The product of its (nonzero) digits is 311040, while the sum is 46.

The square root of 1665964018 is about 40816.2224856735. Note that the first 3 decimals coincide. The cubic root of 1665964018 is about 1185.4644616541.

The spelling of 1665964018 in words is "one billion, six hundred sixty-five million, nine hundred sixty-four thousand, eighteen".