11921817636 has 36 divisors (see below), whose sum is σ = 30517177600. Its totient is φ = 3923635248.

The previous prime is 11921817601. The next prime is 11921817641. The reversal of 11921817636 is 63671812911.

11921817636 is a `hidden beast` number, since 1 + 1 + 9 + 2 + 1 + 8 + 1 + 7 + 636 = 666.

It is a tau number, because it is divible by the number of its divisors (36).

It is a super-3 number, since 3×11921817636³ (a number of 31 digits) contains 333 as substring.

It is a junction number, because it is equal to n+sod(n) for n = 11921817591 and 11921817600.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2093116 + ... + 2098803.

Almost surely, 2^11921817636 is an apocalyptic number.

It is an amenable number.

11921817636 is an abundant number, since it is smaller than the sum of its proper divisors (18595359964).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

11921817636 is a wasteful number, since it uses less digits than its factorization.

11921817636 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4192008 (or 4192003 counting only the distinct ones).

The product of its digits is 108864, while the sum is 45.

The spelling of 11921817636 in words is "eleven billion, nine hundred twenty-one million, eight hundred seventeen thousand, six hundred thirty-six".