13665213540 has 480 divisors, whose sum is σ = 49997122560. Its totient is φ = 3091737600.

The previous prime is 13665213539. The next prime is 13665213557. The reversal of 13665213540 is 4531256631.

13665213540 is a `hidden beast` number, since 1 + 3 + 66 + 52 + 1 + 3 + 540 = 666.

It is a super-2 number, since 2×13665213540² (a number of 21 digits) contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a junction number, because it is equal to n+sod(n) for n = 13665213495 and 13665213504.

It is an unprimeable number.

It is a polite number, since it can be written in 159 ways as a sum of consecutive naturals, for example, 16019754 + ... + 16020606.

It is an arithmetic number, because the mean of its divisors is an integer number (104160672).

Almost surely, 2^13665213540 is an apocalyptic number.

13665213540 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 13665213540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24998561280).

13665213540 is an abundant number, since it is smaller than the sum of its proper divisors (36331909020).

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

13665213540 is a wasteful number, since it uses less digits than its factorization.

13665213540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 945 (or 934 counting only the distinct ones).

The product of its (nonzero) digits is 64800, while the sum is 36.

The spelling of 13665213540 in words is "thirteen billion, six hundred sixty-five million, two hundred thirteen thousand, five hundred forty".