21615543340252 has 6 divisors (see below), whose sum is σ = 37827200845448. Its totient is φ = 10807771670124.

The previous prime is 21615543340241. The next prime is 21615543340283. The reversal of 21615543340252 is 25204334551612.

It is a junction number, because it is equal to n+sod(n) for n = 21615543340199 and 21615543340208.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 2701942917528 + ... + 2701942917535.

Almost surely, 2^{21615543340252} is an apocalyptic number.

It is an amenable number.

21615543340252 is a deficient number, since it is larger than the sum of its proper divisors (16211657505196).

21615543340252 is a wasteful number, since it uses less digits than its factorization.

21615543340252 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5403885835067 (or 5403885835065 counting only the distinct ones).

The product of its (nonzero) digits is 864000, while the sum is 43.

Adding to 21615543340252 its reverse (25204334551612), we get a palindrome (46819877891864).

The spelling of 21615543340252 in words is "twenty-one trillion, six hundred fifteen billion, five hundred forty-three million, three hundred forty thousand, two hundred fifty-two".