21050624 has 72 divisors (see below), whose sum is σ = 50920128. Its totient is φ = 8478720.

The previous prime is 21050611. The next prime is 21050629. The reversal of 21050624 is 42605012.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 21050596 and 21050605.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21050629) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 30119 + ... + 30809.

It is an arithmetic number, because the mean of its divisors is an integer number (707224).

Almost surely, 2^21050624 is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21050624, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (25460064).

21050624 is an abundant number, since it is smaller than the sum of its proper divisors (29869504).

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

21050624 is an equidigital number, since it uses as much as digits as its factorization.

21050624 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 731 (or 717 counting only the distinct ones).

The product of its (nonzero) digits is 480, while the sum is 20.

The square root of 21050624 is about 4588.0959013517. The cubic root of 21050624 is about 276.1139346171.

Adding to 21050624 its reverse (42605012), we get a palindrome (63655636).

It can be divided in two parts, 2105062 and 4, that multiplied together give a palindrome (8420248).

The spelling of 21050624 in words is "twenty-one million, fifty thousand, six hundred twenty-four".