21250020305550 has 48 divisors (see below), whose sum is σ = 53694390950640. Its totient is φ = 5559753738240.

The previous prime is 21250020305543. The next prime is 21250020305617. The reversal of 21250020305550 is 5550302005212.

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

It is a congruent 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, 1336471315 + ... + 1336487214.

It is an arithmetic number, because the mean of its divisors is an integer number (1118633144805).

Almost surely, 2^{21250020305550} is an apocalyptic number.

21250020305550 is an abundant number, since it is smaller than the sum of its proper divisors (32444370645090).

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

21250020305550 is a wasteful number, since it uses less digits than its factorization.

21250020305550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2672958597 (or 2672958592 counting only the distinct ones).

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

The spelling of 21250020305550 in words is "twenty-one trillion, two hundred fifty billion, twenty million, three hundred five thousand, five hundred fifty".