13491540 has 72 divisors (see below), whose sum is σ = 43341480. Its totient is φ = 3385344.

The previous prime is 13491529. The next prime is 13491563. The reversal of 13491540 is 4519431.

13491540 is a `hidden beast` number, since 1 + 34 + 91 + 540 = 666.

It can be written as a sum of positive squares in 4 ways, for example, as 617796 + 12873744 = 786^2 + 3588^2 .

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 856 + ... + 5264.

It is an arithmetic number, because the mean of its divisors is an integer number (601965).

Almost surely, 2^13491540 is an apocalyptic number.

13491540 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 13491540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (21670740).

13491540 is an abundant number, since it is smaller than the sum of its proper divisors (29849940).

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

13491540 is a wasteful number, since it uses less digits than its factorization.

13491540 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 4441 (or 4436 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 27.

The square root of 13491540 is about 3673.0831735750. The cubic root of 13491540 is about 238.0604088355.

The spelling of 13491540 in words is "thirteen million, four hundred ninety-one thousand, five hundred forty".