21021123241 has 4 divisors (see below), whose sum is σ = 21130041172. Its totient is φ = 20912205312.

The previous prime is 21021123239. The next prime is 21021123247. The reversal of 21021123241 is 14232112012.

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 3543225625 + 17477897616 = 59525^2 + 132204^2 .

It is a cyclic number.

It is not a de Polignac number, because 21021123241 - 2¹ = 21021123239 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21021123247) 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, 54458676 + ... + 54459061.

It is an arithmetic number, because the mean of its divisors is an integer number (5282510293).

Almost surely, 2^21021123241 is an apocalyptic number.

It is an amenable number.

21021123241 is a deficient number, since it is larger than the sum of its proper divisors (108917931).

21021123241 is a wasteful number, since it uses less digits than its factorization.

21021123241 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 108917930.

The product of its (nonzero) digits is 192, while the sum is 19.

Adding to 21021123241 its reverse (14232112012), we get a palindrome (35253235253).

The spelling of 21021123241 in words is "twenty-one billion, twenty-one million, one hundred twenty-three thousand, two hundred forty-one".