21305060 has 48 divisors (see below), whose sum is σ = 52792320. Its totient is φ = 7067520.

The previous prime is 21305059. The next prime is 21305071. The reversal of 21305060 is 6050312.

It is an unprimeable number.

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, 1886 + ... + 6794.

It is an arithmetic number, because the mean of its divisors is an integer number (1099840).

Almost surely, 2^21305060 is an apocalyptic number.

21305060 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 21305060, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26396160).

21305060 is an abundant number, since it is smaller than the sum of its proper divisors (31487260).

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

21305060 is a wasteful number, since it uses less digits than its factorization.

21305060 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4956 (or 4954 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 17.

The square root of 21305060 is about 4615.7404606412. The cubic root of 21305060 is about 277.2219328582.

Adding to 21305060 its reverse (6050312), we get a palindrome (27355372).

The spelling of 21305060 in words is "twenty-one million, three hundred five thousand, sixty".