13191720 has 64 divisors (see below), whose sum is σ = 39839040. Its totient is φ = 3494400.

The previous prime is 13191713. The next prime is 13191727. The reversal of 13191720 is 2719131.

It is an interprime number because it is at equal distance from previous prime (13191713) and next prime (13191727).

It is a Harshad number since it is a multiple of its sum of digits (24).

It is not an unprimeable number, because it can be changed into a prime (13191727) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 25060 + ... + 25580.

It is an arithmetic number, because the mean of its divisors is an integer number (622485).

Almost surely, 2^13191720 is an apocalyptic number.

13191720 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 13191720, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (19919520).

13191720 is an abundant number, since it is smaller than the sum of its proper divisors (26647320).

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

13191720 is a wasteful number, since it uses less digits than its factorization.

13191720 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 746 (or 742 counting only the distinct ones).

The product of its (nonzero) digits is 378, while the sum is 24.

The square root of 13191720 is about 3632.0407486701. The cubic root of 13191720 is about 236.2837246444.

The spelling of 13191720 in words is "thirteen million, one hundred ninety-one thousand, seven hundred twenty".