21031543550 has 48 divisors (see below), whose sum is σ = 40096451520. Its totient is φ = 8203647360.

The previous prime is 21031543549. The next prime is 21031543567. The reversal of 21031543550 is 5534513012.

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, 634796 + ... + 667104.

It is an arithmetic number, because the mean of its divisors is an integer number (835342740).

Almost surely, 2^21031543550 is an apocalyptic number.

21031543550 is a deficient number, since it is larger than the sum of its proper divisors (19064907970).

21031543550 is a wasteful number, since it uses less digits than its factorization.

21031543550 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 32645 (or 32640 counting only the distinct ones).

The product of its (nonzero) digits is 9000, while the sum is 29.

The spelling of 21031543550 in words is "twenty-one billion, thirty-one million, five hundred forty-three thousand, five hundred fifty".