1641215018 has 4 divisors (see below), whose sum is σ = 2461822530. Its totient is φ = 820607508.

The previous prime is 1641215011. The next prime is 1641215027. The reversal of 1641215018 is 8105121461.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 8105121461 = 31 ⋅261455531.

It can be written as a sum of positive squares in only one way, i.e., 1487876329 + 153338689 = 38573^2 + 12383^2 .

It is not an unprimeable number, because it can be changed into a prime (1641215011) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 410303753 + ... + 410303756.

Almost surely, 2^1641215018 is an apocalyptic number.

1641215018 is a deficient number, since it is larger than the sum of its proper divisors (820607512).

1641215018 is an equidigital number, since it uses as much as digits as its factorization.

1641215018 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 820607511.

The product of its (nonzero) digits is 1920, while the sum is 29.

The square root of 1641215018 is about 40511.9120506549. The cubic root of 1641215018 is about 1179.5648634984.

Adding to 1641215018 its reverse (8105121461), we get a palindrome (9746336479).

The spelling of 1641215018 in words is "one billion, six hundred forty-one million, two hundred fifteen thousand, eighteen".