13281649920 has 1728 divisors, whose sum is σ = 64424263680. Its totient is φ = 2554675200.

The previous prime is 13281649879. The next prime is 13281649937. The reversal of 13281649920 is 2994618231.

13281649920 is a `hidden beast` number, since 132 + 8 + 1 + 6 + 499 + 20 = 666.

It is a tau number, because it is divible by the number of its divisors (1728).

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 191 ways as a sum of consecutive naturals, for example, 428440305 + ... + 428440335.

It is an arithmetic number, because the mean of its divisors is an integer number (37282560).

Almost surely, 2^13281649920 is an apocalyptic number.

13281649920 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 13281649920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (32212131840).

13281649920 is an abundant number, since it is smaller than the sum of its proper divisors (51142613760).

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

13281649920 is a wasteful number, since it uses less digits than its factorization.

13281649920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 109 (or 82 counting only the distinct ones).

The product of its (nonzero) digits is 186624, while the sum is 45.

The spelling of 13281649920 in words is "thirteen billion, two hundred eighty-one million, six hundred forty-nine thousand, nine hundred twenty".