21305550450 has 48 divisors (see below), whose sum is σ = 53382520800. Its totient is φ = 5622904320.

The previous prime is 21305550449. The next prime is 21305550473. The reversal of 21305550450 is 5405550312.

It is a happy number.

It is a Harshad number since it is a multiple of its sum of digits (30).

It is a Curzon 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, 717600 + ... + 746699.

It is an arithmetic number, because the mean of its divisors is an integer number (1112135850).

Almost surely, 2^21305550450 is an apocalyptic number.

21305550450 is an abundant number, since it is smaller than the sum of its proper divisors (32076970350).

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

21305550450 is a wasteful number, since it uses less digits than its factorization.

21305550450 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1464411 (or 1464406 counting only the distinct ones).

The product of its (nonzero) digits is 15000, while the sum is 30.

The spelling of 21305550450 in words is "twenty-one billion, three hundred five million, five hundred fifty thousand, four hundred fifty".