21162750 has 128 divisors (see below), whose sum is σ = 62899200. Its totient is φ = 4636800.

The previous prime is 21162749. The next prime is 21162763. The reversal of 21162750 is 5726112.

It is a self number, because there is not a number n which added to its sum of digits gives 21162750.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 152181 + ... + 152319.

It is an arithmetic number, because the mean of its divisors is an integer number (491400).

Almost surely, 2^21162750 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21162750, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (31449600).

21162750 is an abundant number, since it is smaller than the sum of its proper divisors (41736450).

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

21162750 is a wasteful number, since it uses less digits than its factorization.

21162750 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 195 (or 185 counting only the distinct ones).

The product of its (nonzero) digits is 840, while the sum is 24.

The square root of 21162750 is about 4600.2989033323. The cubic root of 21162750 is about 276.6033064050.

Adding to 21162750 its reverse (5726112), we get a palindrome (26888862).

It can be divided in two parts, 21162 and 750, that added together give a palindrome (21912).

The spelling of 21162750 in words is "twenty-one million, one hundred sixty-two thousand, seven hundred fifty".