21253050 has 192 divisors, whose sum is σ = 72495360. Its totient is φ = 4458240.

The previous prime is 21253033. The next prime is 21253093. The reversal of 21253050 is 5035212.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (18).

It is an unprimeable number.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 122764 + ... + 122936.

It is an arithmetic number, because the mean of its divisors is an integer number (377580).

Almost surely, 2^21253050 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21253050, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (36247680).

21253050 is an abundant number, since it is smaller than the sum of its proper divisors (51242310).

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

21253050 is a wasteful number, since it uses less digits than its factorization.

21253050 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 214 (or 203 counting only the distinct ones).

The product of its (nonzero) digits is 300, while the sum is 18.

The square root of 21253050 is about 4610.1030357249. The cubic root of 21253050 is about 276.9961639353.

Adding to 21253050 its reverse (5035212), we get a palindrome (26288262).

The spelling of 21253050 in words is "twenty-one million, two hundred fifty-three thousand, fifty".