11865439872 has 640 divisors, whose sum is σ = 42547317120. Its totient is φ = 3234816000.

The previous prime is 11865439829. The next prime is 11865439877. The reversal of 11865439872 is 27893456811.

11865439872 is a `hidden beast` number, since 1 + 1 + 8 + 6 + 543 + 98 + 7 + 2 = 666.

It is a Harshad number since it is a multiple of its sum of digits (54).

It is not an unprimeable number, because it can be changed into a prime (11865439877) by changing a digit.

It is a polite number, since it can be written in 79 ways as a sum of consecutive naturals, for example, 78578997 + ... + 78579147.

It is an arithmetic number, because the mean of its divisors is an integer number (66480183).

Almost surely, 2^11865439872 is an apocalyptic number.

11865439872 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 11865439872, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21273658560).

11865439872 is an abundant number, since it is smaller than the sum of its proper divisors (30681877248).

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

11865439872 is a wasteful number, since it uses less digits than its factorization.

11865439872 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 254 (or 233 counting only the distinct ones).

The product of its digits is 2903040, while the sum is 54.

The spelling of 11865439872 in words is "eleven billion, eight hundred sixty-five million, four hundred thirty-nine thousand, eight hundred seventy-two".