13091840 has 44 divisors (see below), whose sum is σ = 31417356. Its totient is φ = 5234688.

The previous prime is 13091831. The next prime is 13091849. The reversal of 13091840 is 4819031.

It is an interprime number because it is at equal distance from previous prime (13091831) and next prime (13091849).

It can be written as a sum of positive squares in 2 ways, for example, as 5161984 + 7929856 = 2272^2 + 2816^2 .

It is a hoax number, since the sum of its digits (26) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13091849) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3842 + ... + 6398.

Almost surely, 2^13091840 is an apocalyptic number.

13091840 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 13091840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15708678).

13091840 is an abundant number, since it is smaller than the sum of its proper divisors (18325516).

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

13091840 is an equidigital number, since it uses as much as digits as its factorization.

13091840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2582 (or 2564 counting only the distinct ones).

The product of its (nonzero) digits is 864, while the sum is 26.

The square root of 13091840 is about 3618.2647774866. The cubic root of 13091840 is about 235.6858791252.

It can be divided in two parts, 13091 and 840, that added together give a palindrome (13931).

The spelling of 13091840 in words is "thirteen million, ninety-one thousand, eight hundred forty".