1218204460729 has 3 divisors (see below), whose sum is σ = 1218205564453. Its totient is φ = 1218203357006.

The previous prime is 1218204460727. The next prime is 1218204460801. The reversal of 1218204460729 is 9270644028121.

The square root of 1218204460729 is 1103723.

It is a perfect power (a square), and thus also a powerful number.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is not a de Polignac number, because 1218204460729 - 2¹ = 1218204460727 is a prime.

It is a super-2 number, since 2×1218204460729² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1218204460721) by changing a digit.

It is a polite number, since it can be written in 2 ways as a sum of consecutive naturals, for example, 551862 + ... + 1655584.

Almost surely, 2^{1218204460729} is an apocalyptic number.

1218204460729 is the 1103723-rd square number.

1218204460729 is the 551862-nd centered octagonal number.

It is an amenable number.

1218204460729 is a deficient number, since it is larger than the sum of its proper divisors (1103724).

1218204460729 is an frugal number, since it uses more digits than its factorization.

1218204460729 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2207446 (or 1103723 counting only the distinct ones).

The product of its (nonzero) digits is 387072, while the sum is 46.

The spelling of 1218204460729 in words is "one trillion, two hundred eighteen billion, two hundred four million, four hundred sixty thousand, seven hundred twenty-nine".