13665553920 has 720 divisors, whose sum is σ = 52533816192. Its totient is φ = 3277946880.

The previous prime is 13665553883. The next prime is 13665553931. The reversal of 13665553920 is 2935556631.

13665553920 is a `hidden beast` number, since 1 + 3 + 6 + 6 + 5 + 553 + 92 + 0 = 666.

It is a tau number, because it is divible by the number of its divisors (720).

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 71 ways as a sum of consecutive naturals, for example, 257840614 + ... + 257840666.

Almost surely, 2^13665553920 is an apocalyptic number.

13665553920 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 13665553920, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26266908096).

13665553920 is an abundant number, since it is smaller than the sum of its proper divisors (38868262272).

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

13665553920 is a wasteful number, since it uses less digits than its factorization.

13665553920 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 151 (or 113 counting only the distinct ones).

The product of its (nonzero) digits is 729000, while the sum is 45.

The spelling of 13665553920 in words is "thirteen billion, six hundred sixty-five million, five hundred fifty-three thousand, nine hundred twenty".