13815540 has 36 divisors (see below), whose sum is σ = 41907684. Its totient is φ = 3684096.

The previous prime is 13815533. The next prime is 13815551. The reversal of 13815540 is 4551831.

It can be written as a sum of positive squares in 2 ways, for example, as 1954404 + 11861136 = 1398^2 + 3444^2 .

It is a tau number, because it is divible by the number of its divisors (36).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 38197 + ... + 38556.

Almost surely, 2^13815540 is an apocalyptic number.

13815540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

13815540 is an abundant number, since it is smaller than the sum of its proper divisors (28092144).

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

13815540 is a wasteful number, since it uses less digits than its factorization.

13815540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 76768 (or 76763 counting only the distinct ones).

The product of its (nonzero) digits is 2400, while the sum is 27.

The square root of 13815540 is about 3716.9261493874. The cubic root of 13815540 is about 239.9510316761.

The spelling of 13815540 in words is "thirteen million, eight hundred fifteen thousand, five hundred forty".