21306150 has 72 divisors (see below), whose sum is σ = 57886920. Its totient is φ = 5617920.

The previous prime is 21306149. The next prime is 21306167. The reversal of 21306150 is 5160312.

21306150 is a `hidden beast` number, since 21 + 30 + 615 + 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 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 35 ways as a sum of consecutive naturals, for example, 50641 + ... + 51059.

It is an arithmetic number, because the mean of its divisors is an integer number (803985).

Almost surely, 2^21306150 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21306150, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (28943460).

21306150 is an abundant number, since it is smaller than the sum of its proper divisors (36580770).

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

21306150 is a wasteful number, since it uses less digits than its factorization.

21306150 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 550 (or 542 counting only the distinct ones).

The product of its (nonzero) digits is 180, while the sum is 18.

The square root of 21306150 is about 4615.8585333608. The cubic root of 21306150 is about 277.2266604793.

Adding to 21306150 its reverse (5160312), we get a palindrome (26466462).

The spelling of 21306150 in words is "twenty-one million, three hundred six thousand, one hundred fifty".