21115445450 has 48 divisors (see below), whose sum is σ = 43182664704. Its totient is φ = 7617859200.

The previous prime is 21115445399. The next prime is 21115445467. The reversal of 21115445450 is 5454451112.

It is a happy number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 81299 + ... + 220998.

It is an arithmetic number, because the mean of its divisors is an integer number (899638848).

Almost surely, 2^21115445450 is an apocalyptic number.

21115445450 is an abundant number, since it is smaller than the sum of its proper divisors (22067219254).

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

21115445450 is a wasteful number, since it uses less digits than its factorization.

21115445450 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 302447 (or 302442 counting only the distinct ones).

The product of its (nonzero) digits is 16000, while the sum is 32.

Adding to 21115445450 its reverse (5454451112), we get a palindrome (26569896562).

The spelling of 21115445450 in words is "twenty-one billion, one hundred fifteen million, four hundred forty-five thousand, four hundred fifty".