21115020041 has 4 divisors (see below), whose sum is σ = 21266926800. Its totient is φ = 20963113284.

The previous prime is 21115020019. The next prime is 21115020067. The reversal of 21115020041 is 14002051112.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 21115020041 - 2¹⁸ = 21114757897 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21115020841) 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, 75953171 + ... + 75953448.

It is an arithmetic number, because the mean of its divisors is an integer number (5316731700).

Almost surely, 2^21115020041 is an apocalyptic number.

It is an amenable number.

21115020041 is a deficient number, since it is larger than the sum of its proper divisors (151906759).

21115020041 is a wasteful number, since it uses less digits than its factorization.

21115020041 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 151906758.

The product of its (nonzero) digits is 80, while the sum is 17.

Adding to 21115020041 its reverse (14002051112), we get a palindrome (35117071153).

The spelling of 21115020041 in words is "twenty-one billion, one hundred fifteen million, twenty thousand, forty-one".