21618150 has 48 divisors (see below), whose sum is σ = 53996544. Its totient is φ = 5723680.

The previous prime is 21618133. The next prime is 21618197. The reversal of 21618150 is 5181612.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21618150.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 24619 + ... + 25481.

It is an arithmetic number, because the mean of its divisors is an integer number (1124928).

Almost surely, 2^21618150 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21618150, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26998272).

21618150 is an abundant number, since it is smaller than the sum of its proper divisors (32378394).

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

21618150 is a wasteful number, since it uses less digits than its factorization.

21618150 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1045 (or 1040 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 24.

The square root of 21618150 is about 4649.5322345371. The cubic root of 21618150 is about 278.5733126575.

Adding to 21618150 its reverse (5181612), we get a palindrome (26799762).

It can be divided in two parts, 216 and 18150, that multiplied together give a square (3920400 = 1980²).

The spelling of 21618150 in words is "twenty-one million, six hundred eighteen thousand, one hundred fifty".