21201452250 has 128 divisors (see below), whose sum is σ = 61125891840. Its totient is φ = 4837376000.

The previous prime is 21201452221. The next prime is 21201452323. The reversal of 21201452250 is 5225410212.

It is a Curzon number.

It is a self number, because there is not a number n which added to its sum of digits gives 21201452250.

It is an unprimeable number.

It is a polite number, since it can be written in 63 ways as a sum of consecutive naturals, for example, 64666 + ... + 215834.

It is an arithmetic number, because the mean of its divisors is an integer number (477546030).

Almost surely, 2^21201452250 is an apocalyptic number.

It is a practical number, because each smaller number is the sum of distinct divisors of 21201452250, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (30562945920).

21201452250 is an abundant number, since it is smaller than the sum of its proper divisors (39924439590).

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

21201452250 is a wasteful number, since it uses less digits than its factorization.

21201452250 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 151217 (or 151207 counting only the distinct ones).

The product of its (nonzero) digits is 1600, while the sum is 24.

Adding to 21201452250 its reverse (5225410212), we get a palindrome (26426862462).

The spelling of 21201452250 in words is "twenty-one billion, two hundred one million, four hundred fifty-two thousand, two hundred fifty".