21040041021121 has 16 divisors (see below), whose sum is σ = 22376626191360. Its totient is φ = 19726393674240.

The previous prime is 21040041021119. The next prime is 21040041021151. The reversal of 21040041021121 is 12112014004012.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 21040041021121 - 2¹ = 21040041021119 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (19).

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (21040041021151) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 48970251 + ... + 49398031.

It is an arithmetic number, because the mean of its divisors is an integer number (1398539136960).

Almost surely, 2^{21040041021121} is an apocalyptic number.

It is an amenable number.

21040041021121 is a deficient number, since it is larger than the sum of its proper divisors (1336585170239).

21040041021121 is a wasteful number, since it uses less digits than its factorization.

21040041021121 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 454584.

The product of its (nonzero) digits is 128, while the sum is 19.

Adding to 21040041021121 its reverse (12112014004012), we get a palindrome (33152055025133).

The spelling of 21040041021121 in words is "twenty-one trillion, forty billion, forty-one million, twenty-one thousand, one hundred twenty-one".