1218042505 has 8 divisors (see below), whose sum is σ = 1467339912. Its totient is φ = 970641408.

The previous prime is 1218042451. The next prime is 1218042517. The reversal of 1218042505 is 5052408121.

It can be written as a sum of positive squares in 4 ways, for example, as 333099001 + 884943504 = 18251^2 + 29748^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1218042505 - 2⁷ = 1218042377 is a prime.

It is a Duffinian number.

It is an unprimeable number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 472662 + ... + 475231.

It is an arithmetic number, because the mean of its divisors is an integer number (183417489).

Almost surely, 2^1218042505 is an apocalyptic number.

It is an amenable number.

1218042505 is a deficient number, since it is larger than the sum of its proper divisors (249297407).

1218042505 is an equidigital number, since it uses as much as digits as its factorization.

1218042505 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 948155.

The product of its (nonzero) digits is 3200, while the sum is 28.

The square root of 1218042505 is about 34900.4656845722. The cubic root of 1218042505 is about 1067.9579374481.

The spelling of 1218042505 in words is "one billion, two hundred eighteen million, forty-two thousand, five hundred five".