21152206334642 has 8 divisors (see below), whose sum is σ = 31729733831916. Its totient is φ = 10575628390672.

The previous prime is 21152206334641. The next prime is 21152206334659. The reversal of 21152206334642 is 24643360225112.

It can be written as a sum of positive squares in 2 ways, for example, as 20586084021721 + 566122312921 = 4537189^2 + 752411^2 .

It is a sphenic number, since it is the product of 3 distinct primes.

It is a self number, because there is not a number n which added to its sum of digits gives 21152206334642.

It is not an unprimeable number, because it can be changed into a prime (21152206334641) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 237332633 + ... + 237421740.

Almost surely, 2^{21152206334642} is an apocalyptic number.

21152206334642 is a deficient number, since it is larger than the sum of its proper divisors (10577527497274).

21152206334642 is a wasteful number, since it uses less digits than its factorization.

21152206334642 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 474776652.

The product of its (nonzero) digits is 414720, while the sum is 41.

Adding to 21152206334642 its reverse (24643360225112), we get a palindrome (45795566559754).

The spelling of 21152206334642 in words is "twenty-one trillion, one hundred fifty-two billion, two hundred six million, three hundred thirty-four thousand, six hundred forty-two".