21555120352 has 48 divisors (see below), whose sum is σ = 45780768432. Its totient is φ = 9952184320.

The previous prime is 21555120341. The next prime is 21555120397. The reversal of 21555120352 is 25302155512.

It is a congruent number.

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 344974 + ... + 402637.

It is an arithmetic number, because the mean of its divisors is an integer number (953766009).

Almost surely, 2^21555120352 is an apocalyptic number.

It is an amenable number.

21555120352 is an abundant number, since it is smaller than the sum of its proper divisors (24225648080).

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

21555120352 is a wasteful number, since it uses less digits than its factorization.

21555120352 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 747691 (or 747683 counting only the distinct ones).

The product of its (nonzero) digits is 15000, while the sum is 31.

Adding to 21555120352 its reverse (25302155512), we get a palindrome (46857275864).

The spelling of 21555120352 in words is "twenty-one billion, five hundred fifty-five million, one hundred twenty thousand, three hundred fifty-two".