21115516415541 has 16 divisors (see below), whose sum is σ = 30358637211840. Its totient is φ = 13010844516480.

The previous prime is 21115516415533. The next prime is 21115516415563. The reversal of 21115516415541 is 14551461551112.

It is not a de Polignac number, because 21115516415541 - 2³ = 21115516415533 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 21115516415493 and 21115516415502.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21115516415501) 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, 4517652010 + ... + 4517656683.

It is an arithmetic number, because the mean of its divisors is an integer number (1897414825740).

Almost surely, 2^{21115516415541} is an apocalyptic number.

It is an amenable number.

21115516415541 is a deficient number, since it is larger than the sum of its proper divisors (9243120796299).

21115516415541 is a wasteful number, since it uses less digits than its factorization.

21115516415541 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9035308756.

The product of its digits is 120000, while the sum is 42.

Adding to 21115516415541 its reverse (14551461551112), we get a palindrome (35666977966653).

The spelling of 21115516415541 in words is "twenty-one trillion, one hundred fifteen billion, five hundred sixteen million, four hundred fifteen thousand, five hundred forty-one".