21021121120021 has 32 divisors (see below), whose sum is σ = 25048993775616. Its totient is φ = 17440433472000.

The previous prime is 21021121120019. The next prime is 21021121120031. The reversal of 21021121120021 is 12002112112012.

It is not a de Polignac number, because 21021121120021 - 2¹ = 21021121120019 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21021121119977 and 21021121120004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21021121120031) by changing a digit.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 18318076 + ... + 19431781.

It is an arithmetic number, because the mean of its divisors is an integer number (782781055488).

Almost surely, 2^{21021121120021} is an apocalyptic number.

It is an amenable number.

21021121120021 is a deficient number, since it is larger than the sum of its proper divisors (4027872655595).

21021121120021 is a wasteful number, since it uses less digits than its factorization.

21021121120021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 37749993.

The product of its (nonzero) digits is 32, while the sum is 16.

Adding to 21021121120021 its reverse (12002112112012), we get a palindrome (33023233232033).

The spelling of 21021121120021 in words is "twenty-one trillion, twenty-one billion, one hundred twenty-one million, one hundred twenty thousand, twenty-one".