21253121050 has 48 divisors (see below), whose sum is σ = 46635443712. Its totient is φ = 7051723200.

The previous prime is 21253121009. The next prime is 21253121051. The reversal of 21253121050 is 5012135212.

It is not an unprimeable number, because it can be changed into a prime (21253121051) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 968557 + ... + 990256.

It is an arithmetic number, because the mean of its divisors is an integer number (971571744).

Almost surely, 2^21253121050 is an apocalyptic number.

21253121050 is an abundant number, since it is smaller than the sum of its proper divisors (25382322662).

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

21253121050 is a wasteful number, since it uses less digits than its factorization.

21253121050 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1958863 (or 1958858 counting only the distinct ones).

The product of its (nonzero) digits is 600, while the sum is 22.

Adding to 21253121050 its reverse (5012135212), we get a palindrome (26265256262).

The spelling of 21253121050 in words is "twenty-one billion, two hundred fifty-three million, one hundred twenty-one thousand, fifty".