13213440 has 216 divisors, whose sum is σ = 48467328. Its totient is φ = 3317760.

The previous prime is 13213423. The next prime is 13213441. The reversal of 13213440 is 4431231.

13213440 is a `hidden beast` number, since 1 + 321 + 344 + 0 = 666.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13213441) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 357102 + ... + 357138.

Almost surely, 2^13213440 is an apocalyptic number.

13213440 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 13213440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (24233664).

13213440 is an abundant number, since it is smaller than the sum of its proper divisors (35253888).

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

13213440 is a wasteful number, since it uses less digits than its factorization.

13213440 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 95 (or 78 counting only the distinct ones).

The product of its (nonzero) digits is 288, while the sum is 18.

The square root of 13213440 is about 3635.0295734698. The cubic root of 13213440 is about 236.4133329249.

Adding to 13213440 its reverse (4431231), we get a palindrome (17644671).

It can be divided in two parts, 1321 and 3440, that added together give a square (4761 = 69²).

The spelling of 13213440 in words is "thirteen million, two hundred thirteen thousand, four hundred forty".