11981899044 has 18 divisors (see below), whose sum is σ = 30287578230. Its totient is φ = 3993966336.

The previous prime is 11981899003. The next prime is 11981899049. The reversal of 11981899044 is 44099818911.

It can be written as a sum of positive squares in only one way, i.e., 9596553444 + 2385345600 = 97962^2 + 48840^2 .

It is a tau number, because it is divible by the number of its divisors (18).

It is a super-2 number, since 2×11981899044² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (11981899049) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 166415229 + ... + 166415300.

It is an arithmetic number, because the mean of its divisors is an integer number (1682643235).

Almost surely, 2^11981899044 is an apocalyptic number.

It is an amenable number.

11981899044 is an abundant number, since it is smaller than the sum of its proper divisors (18305679186).

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

11981899044 is a wasteful number, since it uses less digits than its factorization.

11981899044 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 332830539 (or 332830534 counting only the distinct ones).

The product of its (nonzero) digits is 746496, while the sum is 54.

The spelling of 11981899044 in words is "eleven billion, nine hundred eighty-one million, eight hundred ninety-nine thousand, forty-four".