21183553168 has 20 divisors (see below), whose sum is σ = 42152409340. Its totient is φ = 10305512064.

The previous prime is 21183553141. The next prime is 21183553211. The reversal of 21183553168 is 86135538112.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 20099299984 + 1084253184 = 141772^2 + 32928^2 .

It is an unprimeable number.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 17890923 + ... + 17892106.

It is an arithmetic number, because the mean of its divisors is an integer number (2107620467).

Almost surely, 2^21183553168 is an apocalyptic number.

It is an amenable number.

21183553168 is a deficient number, since it is larger than the sum of its proper divisors (20968856172).

21183553168 is a wasteful number, since it uses less digits than its factorization.

21183553168 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 35783074 (or 35783068 counting only the distinct ones).

The product of its digits is 172800, while the sum is 43.

The spelling of 21183553168 in words is "twenty-one billion, one hundred eighty-three million, five hundred fifty-three thousand, one hundred sixty-eight".