1531218818 has 4 divisors (see below), whose sum is σ = 2296828230. Its totient is φ = 765609408.

The previous prime is 1531218803. The next prime is 1531218827. The reversal of 1531218818 is 8188121351.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in only one way, i.e., 1497148249 + 34070569 = 38693^2 + 5837^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 382804703 + ... + 382804706.

Almost surely, 2^1531218818 is an apocalyptic number.

1531218818 is a deficient number, since it is larger than the sum of its proper divisors (765609412).

1531218818 is an equidigital number, since it uses as much as digits as its factorization.

1531218818 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 765609411.

The product of its digits is 15360, while the sum is 38.

The square root of 1531218818 is about 39130.7911752369. The cubic root of 1531218818 is about 1152.6012491452.

The spelling of 1531218818 in words is "one billion, five hundred thirty-one million, two hundred eighteen thousand, eight hundred eighteen".