1218540601 has 4 divisors (see below), whose sum is σ = 1235233012. Its totient is φ = 1201848192.

The previous prime is 1218540599. The next prime is 1218540619. The reversal of 1218540601 is 1060458121.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1060458121 = 22279 ⋅47599.

It can be written as a sum of positive squares in 2 ways, for example, as 640090000 + 578450601 = 25300^2 + 24051^2 .

It is a cyclic number.

It is not a de Polignac number, because 1218540601 - 2¹ = 1218540599 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 1218540601.

It is not an unprimeable number, because it can be changed into a prime (1218540691) by changing a digit.

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 in 3 ways as a sum of consecutive naturals, for example, 8346096 + ... + 8346241.

It is an arithmetic number, because the mean of its divisors is an integer number (308808253).

Almost surely, 2^1218540601 is an apocalyptic number.

It is an amenable number.

1218540601 is a deficient number, since it is larger than the sum of its proper divisors (16692411).

1218540601 is an equidigital number, since it uses as much as digits as its factorization.

1218540601 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 16692410.

The product of its (nonzero) digits is 1920, while the sum is 28.

The square root of 1218540601 is about 34907.6009058199. The cubic root of 1218540601 is about 1068.1034915048.

Adding to 1218540601 its reverse (1060458121), we get a palindrome (2278998722).

It can be divided in two parts, 1218540 and 601, that added together give a triangular number (1219141 = T₁₅₆₁).

The spelling of 1218540601 in words is "one billion, two hundred eighteen million, five hundred forty thousand, six hundred one".