21422550 has 96 divisors (see below), whose sum is σ = 58281984. Its totient is φ = 5184000.

The previous prime is 21422537. The next prime is 21422551. The reversal of 21422550 is 5522412.

It is a happy number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21422551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 47 ways as a sum of consecutive naturals, for example, 78915 + ... + 79185.

It is an arithmetic number, because the mean of its divisors is an integer number (607104).

Almost surely, 2^21422550 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21422550, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (29140992).

21422550 is an abundant number, since it is smaller than the sum of its proper divisors (36859434).

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

21422550 is a wasteful number, since it uses less digits than its factorization.

21422550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 334 (or 329 counting only the distinct ones).

The product of its (nonzero) digits is 800, while the sum is 21.

The square root of 21422550 is about 4628.4500645464. The cubic root of 21422550 is about 277.7305931706.

Adding to 21422550 its reverse (5522412), we get a palindrome (26944962).

The spelling of 21422550 in words is "twenty-one million, four hundred twenty-two thousand, five hundred fifty".