21416550 has 48 divisors (see below), whose sum is σ = 53931072. Its totient is φ = 5623200.

The previous prime is 21416543. The next prime is 21416561. The reversal of 21416550 is 5561412.

It is a super-2 number, since 2×21416550² = 917337227805000, which contains 22 as substring.

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 21416550.

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, 8985 + ... + 11115.

It is an arithmetic number, because the mean of its divisors is an integer number (1123564).

Almost surely, 2^21416550 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21416550, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26965536).

21416550 is an abundant number, since it is smaller than the sum of its proper divisors (32514522).

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

21416550 is a wasteful number, since it uses less digits than its factorization.

21416550 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2213 (or 2208 counting only the distinct ones).

The product of its (nonzero) digits is 1200, while the sum is 24.

The square root of 21416550 is about 4627.8018540123. The cubic root of 21416550 is about 277.7046619415.

Adding to 21416550 its reverse (5561412), we get a palindrome (26977962).

The spelling of 21416550 in words is "twenty-one million, four hundred sixteen thousand, five hundred fifty".