13664540 has 24 divisors (see below), whose sum is σ = 29364720. Its totient is φ = 5338368.

The previous prime is 13664533. The next prime is 13664543. The reversal of 13664540 is 4546631.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13664543) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7085 + ... + 8804.

It is an arithmetic number, because the mean of its divisors is an integer number (1223530).

Almost surely, 2^13664540 is an apocalyptic number.

13664540 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

13664540 is an abundant number, since it is smaller than the sum of its proper divisors (15700180).

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

13664540 is a wasteful number, since it uses less digits than its factorization.

13664540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15941 (or 15939 counting only the distinct ones).

The product of its (nonzero) digits is 8640, while the sum is 29.

The square root of 13664540 is about 3696.5578583325. The cubic root of 13664540 is about 239.0736279867.

The spelling of 13664540 in words is "thirteen million, six hundred sixty-four thousand, five hundred forty".