21321011431441 has 4 divisors (see below), whose sum is σ = 21321029615652. Its totient is φ = 21320993247232.

The previous prime is 21321011431439. The next prime is 21321011431463. The reversal of 21321011431441 is 14413411012312.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 20030288221441 + 1290723210000 = 4475521^2 + 1136100^2 .

It is a cyclic number.

It is not a de Polignac number, because 21321011431441 - 2¹ = 21321011431439 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21321011431471) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 7202440 + ... + 9721993.

It is an arithmetic number, because the mean of its divisors is an integer number (5330257403913).

Almost surely, 2^{21321011431441} is an apocalyptic number.

It is an amenable number.

21321011431441 is a deficient number, since it is larger than the sum of its proper divisors (18184211).

21321011431441 is a wasteful number, since it uses less digits than its factorization.

21321011431441 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 18184210.

The product of its (nonzero) digits is 2304, while the sum is 28.

Adding to 21321011431441 its reverse (14413411012312), we get a palindrome (35734422443753).

The spelling of 21321011431441 in words is "twenty-one trillion, three hundred twenty-one billion, eleven million, four hundred thirty-one thousand, four hundred forty-one".