21361260 has 48 divisors (see below), whose sum is σ = 60643296. Its totient is φ = 5617152.

The previous prime is 21361259. The next prime is 21361261. The reversal of 21361260 is 6216312.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (21361259) and next prime (21361261).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21361261) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 1942 + ... + 6818.

It is an arithmetic number, because the mean of its divisors is an integer number (1263402).

Almost surely, 2^21361260 is an apocalyptic number.

21361260 is a gapful number since it is divisible by the number (20) 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 21361260, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30321648).

21361260 is an abundant number, since it is smaller than the sum of its proper divisors (39282036).

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

21361260 is a wasteful number, since it uses less digits than its factorization.

21361260 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4962 (or 4960 counting only the distinct ones).

The product of its (nonzero) digits is 432, while the sum is 21.

The square root of 21361260 is about 4621.8243151379. The cubic root of 21361260 is about 277.4654774033.

Adding to 21361260 its reverse (6216312), we get a palindrome (27577572).

The spelling of 21361260 in words is "twenty-one million, three hundred sixty-one thousand, two hundred sixty".