11820503721 has 32 divisors (see below), whose sum is σ = 17099367040. Its totient is φ = 7263127872.

The previous prime is 11820503633. The next prime is 11820503749. The reversal of 11820503721 is 12730502811.

It is not a de Polignac number, because 11820503721 - 2⁷ = 11820503593 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (11820503771) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 7400895 + ... + 7402491.

It is an arithmetic number, because the mean of its divisors is an integer number (534355220).

Almost surely, 2^11820503721 is an apocalyptic number.

It is an amenable number.

11820503721 is a deficient number, since it is larger than the sum of its proper divisors (5278863319).

11820503721 is a wasteful number, since it uses less digits than its factorization.

11820503721 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2762 (or 2736 counting only the distinct ones).

The product of its (nonzero) digits is 3360, while the sum is 30.

The spelling of 11820503721 in words is "eleven billion, eight hundred twenty million, five hundred three thousand, seven hundred twenty-one".