13971240 has 72 divisors (see below), whose sum is σ = 45638190. Its totient is φ = 3706752.

The previous prime is 13971227. The next prime is 13971247. The reversal of 13971240 is 4217931.

13971240 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It can be written as a sum of positive squares in 3 ways, for example, as 13527684 + 443556 = 3678^2 + 666^2 .

It is a tau number, because it is divible by the number of its divisors (72).

It is a hoax number, since the sum of its digits (27) coincides with the sum of the digits of its distinct prime factors.

It is not an unprimeable number, because it can be changed into a prime (13971247) by changing a digit.

It is a polite number, since it can be written in 17 ways as a sum of consecutive naturals, for example, 70822 + ... + 71018.

Almost surely, 2^13971240 is an apocalyptic number.

13971240 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 13971240, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22819095).

13971240 is an abundant number, since it is smaller than the sum of its proper divisors (31666950).

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

13971240 is a wasteful number, since it uses less digits than its factorization.

13971240 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 411 (or 207 counting only the distinct ones).

The product of its (nonzero) digits is 1512, while the sum is 27.

The square root of 13971240 is about 3737.8121943190. The cubic root of 13971240 is about 240.8490759163.

The spelling of 13971240 in words is "thirteen million, nine hundred seventy-one thousand, two hundred forty".