21352254 has 64 divisors (see below), whose sum is σ = 53844480. Its totient is φ = 5483520.

The previous prime is 21352249. The next prime is 21352291. The reversal of 21352254 is 45225312.

It is a Curzon number.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 52002 + ... + 52410.

It is an arithmetic number, because the mean of its divisors is an integer number (841320).

Almost surely, 2^21352254 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21352254, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (26922240).

21352254 is an abundant number, since it is smaller than the sum of its proper divisors (32492226).

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

21352254 is a wasteful number, since it uses less digits than its factorization.

21352254 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 545.

The product of its digits is 2400, while the sum is 24.

The square root of 21352254 is about 4620.8499218217. The cubic root of 21352254 is about 277.4264783719.

Adding to 21352254 its reverse (45225312), we get a palindrome (66577566).

The spelling of 21352254 in words is "twenty-one million, three hundred fifty-two thousand, two hundred fifty-four".