21953024 has 40 divisors (see below), whose sum is σ = 44746020. Its totient is φ = 10756096.

The previous prime is 21953011. The next prime is 21953033. The reversal of 21953024 is 42035912.

It can be written as a sum of positive squares in 2 ways, for example, as 19642624 + 2310400 = 4432^2 + 1520^2 .

It is a junction number, because it is equal to n+sod(n) for n = 21952984 and 21953002.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 26732 + ... + 27540.

Almost surely, 2^21953024 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 21953024, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (22373010).

21953024 is an abundant number, since it is smaller than the sum of its proper divisors (22792996).

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

21953024 is an frugal number, since it uses more digits than its factorization.

21953024 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 880 (or 864 counting only the distinct ones).

The product of its (nonzero) digits is 2160, while the sum is 26.

The square root of 21953024 is about 4685.4054253608. The cubic root of 21953024 is about 280.0043536738.

Adding to 21953024 its reverse (42035912), we get a palindrome (63988936).

The spelling of 21953024 in words is "twenty-one million, nine hundred fifty-three thousand, twenty-four".