21533553550 has 24 divisors (see below), whose sum is σ = 40212004392. Its totient is φ = 8579100000.

The previous prime is 21533553487. The next prime is 21533553583. The reversal of 21533553550 is 5535533512.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 845361 + ... + 870460.

It is an arithmetic number, because the mean of its divisors is an integer number (1675500183).

Almost surely, 2^21533553550 is an apocalyptic number.

21533553550 is a deficient number, since it is larger than the sum of its proper divisors (18678450842).

21533553550 is a wasteful number, since it uses less digits than its factorization.

21533553550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1716084 (or 1716079 counting only the distinct ones).

The product of its (nonzero) digits is 168750, while the sum is 37.

The spelling of 21533553550 in words is "twenty-one billion, five hundred thirty-three million, five hundred fifty-three thousand, five hundred fifty".