21152543051653 has 12 divisors (see below), whose sum is σ = 22934923188228. Its totient is φ = 19499766648960.

The previous prime is 21152543051551. The next prime is 21152543051669. The reversal of 21152543051653 is 35615034525112.

It can be written as a sum of positive squares in 6 ways, for example, as 10170888207489 + 10981654844164 = 3189183^2 + 3313858^2 .

It is not a de Polignac number, because 21152543051653 - 2¹⁷ = 21152542920581 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21152543051153) 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, 82107250 + ... + 82364467.

It is an arithmetic number, because the mean of its divisors is an integer number (1911243599019).

Almost surely, 2^{21152543051653} is an apocalyptic number.

It is an amenable number.

21152543051653 is a deficient number, since it is larger than the sum of its proper divisors (1782380136575).

21152543051653 is a wasteful number, since it uses less digits than its factorization.

21152543051653 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 164472504 (or 164472491 counting only the distinct ones).

The product of its (nonzero) digits is 540000, while the sum is 43.

Adding to 21152543051653 its reverse (35615034525112), we get a palindrome (56767577576765).

The spelling of 21152543051653 in words is "twenty-one trillion, one hundred fifty-two billion, five hundred forty-three million, fifty-one thousand, six hundred fifty-three".