21042123552 has 72 divisors (see below), whose sum is σ = 59852834496. Its totient is φ = 7012365696.

The previous prime is 21042123539. The next prime is 21042123559. The reversal of 21042123552 is 25532124012.

21042123552 is a `hidden beast` number, since 2 + 1 + 0 + 421 + 235 + 5 + 2 = 666.

It is a tau number, because it is divible by the number of its divisors (72).

It is not an unprimeable number, because it can be changed into a prime (21042123559) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 2001253 + ... + 2011739.

It is an arithmetic number, because the mean of its divisors is an integer number (831289368).

Almost surely, 2^21042123552 is an apocalyptic number.

It is an amenable number.

21042123552 is an abundant number, since it is smaller than the sum of its proper divisors (38810710944).

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

21042123552 is a wasteful number, since it uses less digits than its factorization.

21042123552 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 17470 (or 17459 counting only the distinct ones).

The product of its (nonzero) digits is 4800, while the sum is 27.

Adding to 21042123552 its reverse (25532124012), we get a palindrome (46574247564).

The spelling of 21042123552 in words is "twenty-one billion, forty-two million, one hundred twenty-three thousand, five hundred fifty-two".