21515411543053 has 16 divisors (see below), whose sum is σ = 22923106786944. Its totient is φ = 20123563276800.

The previous prime is 21515411542997. The next prime is 21515411543069. The reversal of 21515411543053 is 35034511451512.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-21515411543053 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21515411542997 and 21515411543015.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21515411543083) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 10565401 + ... + 12436177.

It is an arithmetic number, because the mean of its divisors is an integer number (1432694174184).

Almost surely, 2^{21515411543053} is an apocalyptic number.

It is an amenable number.

21515411543053 is a deficient number, since it is larger than the sum of its proper divisors (1407695243891).

21515411543053 is a wasteful number, since it uses less digits than its factorization.

21515411543053 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1875012.

The product of its (nonzero) digits is 180000, while the sum is 40.

Adding to 21515411543053 its reverse (35034511451512), we get a palindrome (56549922994565).

The spelling of 21515411543053 in words is "twenty-one trillion, five hundred fifteen billion, four hundred eleven million, five hundred forty-three thousand, fifty-three".