12991085280 has 144 divisors (see below), whose sum is σ = 44656348464. Its totient is φ = 3438950400.

The previous prime is 12991085273. The next prime is 12991085287. The reversal of 12991085280 is 8258019921.

12991085280 is a `hidden beast` number, since 1 + 299 + 1 + 0 + 85 + 280 = 666.

It is an interprime number because it is at equal distance from previous prime (12991085273) and next prime (12991085287).

It is a tau number, because it is divible by the number of its divisors (144).

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

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12991085287) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 164355 + ... + 230205.

It is an arithmetic number, because the mean of its divisors is an integer number (310113531).

Almost surely, 2^12991085280 is an apocalyptic number.

12991085280 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 12991085280, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22328174232).

12991085280 is an abundant number, since it is smaller than the sum of its proper divisors (31665263184).

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

12991085280 is a wasteful number, since it uses less digits than its factorization.

12991085280 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 66009 (or 65998 counting only the distinct ones).

The product of its (nonzero) digits is 103680, while the sum is 45.

The spelling of 12991085280 in words is "twelve billion, nine hundred ninety-one million, eighty-five thousand, two hundred eighty".