21152515331453 has 6 divisors (see below), whose sum is σ = 23250285447102. Its totient is φ = 19229559392120.

The previous prime is 21152515331429. The next prime is 21152515331483. The reversal of 21152515331453 is 35413351525112.

It can be written as a sum of positive squares in only one way, i.e., 10769961824644 + 10382553506809 = 3281762^2 + 3222197^2 .

It is not a de Polignac number, because 21152515331453 - 2³² = 21148220364157 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 21152515331453.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21152515331483) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 87407088026 + ... + 87407088267.

It is an arithmetic number, because the mean of its divisors is an integer number (3875047574517).

Almost surely, 2^{21152515331453} is an apocalyptic number.

It is an amenable number.

21152515331453 is a deficient number, since it is larger than the sum of its proper divisors (2097770115649).

21152515331453 is a wasteful number, since it uses less digits than its factorization.

21152515331453 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 174814176315 (or 174814176304 counting only the distinct ones).

The product of its digits is 270000, while the sum is 41.

Adding to 21152515331453 its reverse (35413351525112), we get a palindrome (56565866856565).

The spelling of 21152515331453 in words is "twenty-one trillion, one hundred fifty-two billion, five hundred fifteen million, three hundred thirty-one thousand, four hundred fifty-three".