13021540 has 48 divisors (see below), whose sum is σ = 31457664. Its totient is φ = 4435200.

The previous prime is 13021529. The next prime is 13021543. The reversal of 13021540 is 4512031.

It is a plaindrome in base 15.

It is not an unprimeable number, because it can be changed into a prime (13021543) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 39175 + ... + 39505.

It is an arithmetic number, because the mean of its divisors is an integer number (655368).

Almost surely, 2^13021540 is an apocalyptic number.

13021540 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 13021540, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (15728832).

13021540 is an abundant number, since it is smaller than the sum of its proper divisors (18436124).

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

13021540 is a wasteful number, since it uses less digits than its factorization.

13021540 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 628 (or 626 counting only the distinct ones).

The product of its (nonzero) digits is 120, while the sum is 16.

The square root of 13021540 is about 3608.5370997123. The cubic root of 13021540 is about 235.2632631355.

Adding to 13021540 its reverse (4512031), we get a palindrome (17533571).

The spelling of 13021540 in words is "thirteen million, twenty-one thousand, five hundred forty".