11418918297721 has 27 divisors (see below), whose sum is σ = 12686108295567. Its totient is φ = 10270571879040.

The previous prime is 11418918297713. The next prime is 11418918297757. The reversal of 11418918297721 is 12779281981411.

The square root of 11418918297721 is 3379189.

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

It can be written as a sum of positive squares in only one way, i.e., 5127530004025 + 6291388293696 = 2264405^2 + 2508264^2 .

It is not a de Polignac number, because 11418918297721 - 2³ = 11418918297713 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 11418918297721.

It is not an unprimeable number, because it can be changed into a prime (11418918297221) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 26 ways as a sum of consecutive naturals, for example, 3605593080 + ... + 3605596246.

Almost surely, 2^{11418918297721} is an apocalyptic number.

11418918297721 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

11418918297721 is the 3379189-th square number.

11418918297721 is the 1689595-th centered octagonal number.

It is an amenable number.

11418918297721 is a deficient number, since it is larger than the sum of its proper divisors (1267189997846).

11418918297721 is an frugal number, since it uses more digits than its factorization.

11418918297721 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6550 (or 3275 counting only the distinct ones).

The product of its digits is 4064256, while the sum is 61.

The spelling of 11418918297721 in words is "eleven trillion, four hundred eighteen billion, nine hundred eighteen million, two hundred ninety-seven thousand, seven hundred twenty-one".