1644064018 has 4 divisors (see below), whose sum is σ = 2466096030. Its totient is φ = 822032008.

The previous prime is 1644064003. The next prime is 1644064141. The reversal of 1644064018 is 8104604461.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 8104604461 = 23 ⋅352374107.

It can be written as a sum of positive squares in only one way, i.e., 939851649 + 704212369 = 30657^2 + 26537^2 .

It is a super-3 number, since 3×1644064018³ (a number of 29 digits) contains 333 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, 411016003 + ... + 411016006.

Almost surely, 2^1644064018 is an apocalyptic number.

1644064018 is a deficient number, since it is larger than the sum of its proper divisors (822032012).

1644064018 is an equidigital number, since it uses as much as digits as its factorization.

1644064018 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 822032011.

The product of its (nonzero) digits is 18432, while the sum is 34.

The square root of 1644064018 is about 40547.0593015079. The cubic root of 1644064018 is about 1180.2470080434.

Adding to 1644064018 its reverse (8104604461), we get a palindrome (9748668479).

The spelling of 1644064018 in words is "one billion, six hundred forty-four million, sixty-four thousand, eighteen".