21653234242056 has 48 divisors (see below), whose sum is σ = 58644879668700. Its totient is φ = 7217658150912.

The previous prime is 21653234242027. The next prime is 21653234242091. The reversal of 21653234242056 is 65024243235612.

21653234242056 is a `hidden beast` number, since 2 + 1 + 6 + 532 + 3 + 42 + 4 + 20 + 56 = 666.

It can be written as a sum of positive squares in 2 ways, for example, as 12197793741156 + 9455440500900 = 3492534^2 + 3074970^2 .

It is an unprimeable number.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 4385160 + ... + 7907976.

Almost surely, 2^{21653234242056} is an apocalyptic number.

It is an amenable number.

21653234242056 is an abundant number, since it is smaller than the sum of its proper divisors (36991645426644).

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

21653234242056 is a wasteful number, since it uses less digits than its factorization.

21653234242056 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 3608198 (or 3608191 counting only the distinct ones).

The product of its (nonzero) digits is 2073600, while the sum is 45.

Adding to 21653234242056 its reverse (65024243235612), we get a palindrome (86677477477668).

The spelling of 21653234242056 in words is "twenty-one trillion, six hundred fifty-three billion, two hundred thirty-four million, two hundred forty-two thousand, fifty-six".