13640235840 has 1344 divisors, whose sum is σ = 63795859200. Its totient is φ = 2709504000.

The previous prime is 13640235823. The next prime is 13640235857. The reversal of 13640235840 is 4853204631.

13640235840 is a `hidden beast` number, since 1 + 3 + 640 + 2 + 3 + 5 + 8 + 4 + 0 = 666.

It is an interprime number because it is at equal distance from previous prime (13640235823) and next prime (13640235857).

It is a tau number, because it is divible by the number of its divisors (1344).

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 = 13640235795 and 13640235804.

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, 135051790 + ... + 135051890.

Almost surely, 2^13640235840 is an apocalyptic number.

13640235840 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 13640235840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31897929600).

13640235840 is an abundant number, since it is smaller than the sum of its proper divisors (50155623360).

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

13640235840 is a wasteful number, since it uses less digits than its factorization.

13640235840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 181 (or 158 counting only the distinct ones).

The product of its (nonzero) digits is 69120, while the sum is 36.

The spelling of 13640235840 in words is "thirteen billion, six hundred forty million, two hundred thirty-five thousand, eight hundred forty".