13781240 has 32 divisors (see below), whose sum is σ = 33827760. Its totient is φ = 5011200.

The previous prime is 13781239. The next prime is 13781263. The reversal of 13781240 is 4218731.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15221 + ... + 16100.

Almost surely, 2^13781240 is an apocalyptic number.

13781240 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

13781240 is an abundant number, since it is smaller than the sum of its proper divisors (20046520).

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

13781240 is a wasteful number, since it uses less digits than its factorization.

13781240 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 31343 (or 31339 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 26.

The square root of 13781240 is about 3712.3092543591. The cubic root of 13781240 is about 239.7522907181.

Adding to 13781240 its reverse (4218731), we get a palindrome (17999971).

The spelling of 13781240 in words is "thirteen million, seven hundred eighty-one thousand, two hundred forty".