21115542210321 has 32 divisors (see below), whose sum is σ = 31926503952000. Its totient is φ = 12306042574848.

The previous prime is 21115542210317. The next prime is 21115542210379. The reversal of 21115542210321 is 12301224551112.

It is not a de Polignac number, because 21115542210321 - 2² = 21115542210317 is a prime.

It is a super-2 number, since 2×21115542210321² (a number of 27 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (21115542210311) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 2742336 + ... + 7053473.

It is an arithmetic number, because the mean of its divisors is an integer number (997703248500).

Almost surely, 2^{21115542210321} is an apocalyptic number.

It is an amenable number.

21115542210321 is a deficient number, since it is larger than the sum of its proper divisors (10810961741679).

21115542210321 is a wasteful number, since it uses less digits than its factorization.

21115542210321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 9798753.

The product of its (nonzero) digits is 4800, while the sum is 30.

Adding to 21115542210321 its reverse (12301224551112), we get a palindrome (33416766761433).

The spelling of 21115542210321 in words is "twenty-one trillion, one hundred fifteen billion, five hundred forty-two million, two hundred ten thousand, three hundred twenty-one".