13533440 has 72 divisors (see below), whose sum is σ = 33051480. Its totient is φ = 5308416.

The previous prime is 13533439. The next prime is 13533449. The reversal of 13533440 is 4433531.

13533440 = T₄₇₉ + T₄₈₀ + ... + T₅₇₅.

It can be written as a sum of positive squares in 4 ways, for example, as 2027776 + 11505664 = 1424^2 + 3392^2 .

It is not an unprimeable number, because it can be changed into a prime (13533449) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 124106 + ... + 124214.

Almost surely, 2^13533440 is an apocalyptic number.

13533440 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 13533440, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (16525740).

13533440 is an abundant number, since it is smaller than the sum of its proper divisors (19518040).

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

13533440 is an equidigital number, since it uses as much as digits as its factorization.

13533440 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 227 (or 213 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 23.

The square root of 13533440 is about 3678.7824072647. The cubic root of 13533440 is about 238.3065982476.

Adding to 13533440 its reverse (4433531), we get a palindrome (17966971).

Subtracting from 13533440 its reverse (4433531), we obtain a palindrome (9099909).

The spelling of 13533440 in words is "thirteen million, five hundred thirty-three thousand, four hundred forty".