21024041211021 has 4 divisors (see below), whose sum is σ = 28032054948032. Its totient is φ = 14016027474012.

The previous prime is 21024041211007. The next prime is 21024041211079. The reversal of 21024041211021 is 12011214042012.

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 de Polignac number, because none of the positive numbers 2^k-21024041211021 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21024041212021) 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, 3504006868501 + ... + 3504006868506.

It is an arithmetic number, because the mean of its divisors is an integer number (7008013737008).

Almost surely, 2^{21024041211021} is an apocalyptic number.

It is an amenable number.

21024041211021 is a deficient number, since it is larger than the sum of its proper divisors (7008013737011).

21024041211021 is an equidigital number, since it uses as much as digits as its factorization.

21024041211021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7008013737010.

The product of its (nonzero) digits is 256, while the sum is 21.

Adding to 21024041211021 its reverse (12011214042012), we get a palindrome (33035255253033).

The spelling of 21024041211021 in words is "twenty-one trillion, twenty-four billion, forty-one million, two hundred eleven thousand, twenty-one".