21021021020021 has 8 divisors (see below), whose sum is σ = 22932418008864. Its totient is φ = 19109689877520.

The previous prime is 21021021020017. The next prime is 21021021020033. The reversal of 21021021020021 is 12002012012012.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 21021021020021 - 2² = 21021021020017 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21021021019978 and 21021021020005.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21021021020621) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 15792890 + ... + 17072123.

It is an arithmetic number, because the mean of its divisors is an integer number (2866552251108).

Almost surely, 2^{21021021020021} is an apocalyptic number.

It is an amenable number.

21021021020021 is a deficient number, since it is larger than the sum of its proper divisors (1911396988843).

21021021020021 is a wasteful number, since it uses less digits than its factorization.

21021021020021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 32923171.

The product of its (nonzero) digits is 32, while the sum is 14.

Adding to 21021021020021 its reverse (12002012012012), we get a palindrome (33023033032033).

The spelling of 21021021020021 in words is "twenty-one trillion, twenty-one billion, twenty-one million, twenty thousand, twenty-one".