21121002111021 has 8 divisors (see below), whose sum is σ = 28419697030560. Its totient is φ = 13951487632752.

The previous prime is 21121002110947. The next prime is 21121002111043. The reversal of 21121002111021 is 12011120012112.

It is a happy number.

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

It is not a de Polignac number, because 21121002111021 - 2¹⁰ = 21121002109997 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21121002111071) 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, 32295109935 + ... + 32295110588.

It is an arithmetic number, because the mean of its divisors is an integer number (3552462128820).

Almost surely, 2^{21121002111021} is an apocalyptic number.

It is an amenable number.

21121002111021 is a deficient number, since it is larger than the sum of its proper divisors (7298694919539).

21121002111021 is a wasteful number, since it uses less digits than its factorization.

21121002111021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 64590220635.

The product of its (nonzero) digits is 16, while the sum is 15.

Adding to 21121002111021 its reverse (12011120012112), we get a palindrome (33132122123133).

The spelling of 21121002111021 in words is "twenty-one trillion, one hundred twenty-one billion, two million, one hundred eleven thousand, twenty-one".