21556050 has 48 divisors (see below), whose sum is σ = 53916192. Its totient is φ = 5699200.

The previous prime is 21556027. The next prime is 21556057. The reversal of 21556050 is 5065512.

It is a self number, because there is not a number n which added to its sum of digits gives 21556050.

It is not an unprimeable number, because it can be changed into a prime (21556057) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 19102 + ... + 20198.

It is an arithmetic number, because the mean of its divisors is an integer number (1123254).

Almost surely, 2^21556050 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21556050, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26958096).

21556050 is an abundant number, since it is smaller than the sum of its proper divisors (32360142).

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

21556050 is a wasteful number, since it uses less digits than its factorization.

21556050 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1243 (or 1238 counting only the distinct ones).

The product of its (nonzero) digits is 1500, while the sum is 24.

The square root of 21556050 is about 4642.8493406528. The cubic root of 21556050 is about 278.3063148821.

It can be divided in two parts, 215 and 56050, that added together give a palindrome (56265).

The spelling of 21556050 in words is "twenty-one million, five hundred fifty-six thousand, fifty".