21581301271321 has 8 divisors (see below), whose sum is σ = 23547947400000. Its totient is φ = 19615440084240.

The previous prime is 21581301271297. The next prime is 21581301271337. The reversal of 21581301271321 is 12317210318512.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21581301271321 - 2¹¹ = 21581301269273 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21581301271391) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 196177906 + ... + 196287883.

It is an arithmetic number, because the mean of its divisors is an integer number (2943493425000).

Almost surely, 2^{21581301271321} is an apocalyptic number.

It is an amenable number.

21581301271321 is a deficient number, since it is larger than the sum of its proper divisors (1966646128679).

21581301271321 is a wasteful number, since it uses less digits than its factorization.

21581301271321 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 392470799.

The product of its (nonzero) digits is 20160, while the sum is 37.

Adding to 21581301271321 its reverse (12317210318512), we get a palindrome (33898511589833).

The spelling of 21581301271321 in words is "twenty-one trillion, five hundred eighty-one billion, three hundred one million, two hundred seventy-one thousand, three hundred twenty-one".