13645840 has 40 divisors (see below), whose sum is σ = 34169688. Its totient is φ = 5038080.

The previous prime is 13645837. The next prime is 13645847. The reversal of 13645840 is 4854631.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 73984 + 13571856 = 272^2 + 3684^2 .

It is a tau number, because it is divible by the number of its divisors (40).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13645847) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 5521 + ... + 7600.

Almost surely, 2^13645840 is an apocalyptic number.

13645840 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

13645840 is an abundant number, since it is smaller than the sum of its proper divisors (20523848).

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

13645840 is a wasteful number, since it uses less digits than its factorization.

13645840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 13147 (or 13141 counting only the distinct ones).

The product of its (nonzero) digits is 11520, while the sum is 31.

The square root of 13645840 is about 3694.0276122411. The cubic root of 13645840 is about 238.9645203310.

The spelling of 13645840 in words is "thirteen million, six hundred forty-five thousand, eight hundred forty".