11951439840 has 288 divisors, whose sum is σ = 42744330720. Its totient is φ = 3153199104.

The previous prime is 11951439817. The next prime is 11951439859. The reversal of 11951439840 is 4893415911.

11951439840 is a `hidden beast` number, since 1 + 1 + 9 + 514 + 3 + 98 + 40 = 666.

It is a tau number, because it is divible by the number of its divisors (288).

It is a hoax number, since the sum of its digits (45) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 3769776 + ... + 3772944.

It is an arithmetic number, because the mean of its divisors is an integer number (148417815).

Almost surely, 2^11951439840 is an apocalyptic number.

11951439840 is a gapful number since it is divisible by the number (10) 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 11951439840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21372165360).

11951439840 is an abundant number, since it is smaller than the sum of its proper divisors (30792890880).

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

11951439840 is an equidigital number, since it uses as much as digits as its factorization.

11951439840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3296 (or 3276 counting only the distinct ones).

The product of its (nonzero) digits is 155520, while the sum is 45.

The spelling of 11951439840 in words is "eleven billion, nine hundred fifty-one million, four hundred thirty-nine thousand, eight hundred forty".