21221021002021 has 8 divisors (see below), whose sum is σ = 21224066880960. Its totient is φ = 21217975359552.

The previous prime is 21221021001919. The next prime is 21221021002033. The reversal of 21221021002021 is 12020012012212.

It is a happy number.

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

It is a cyclic number.

It is not a de Polignac number, because 21221021002021 - 2¹³ = 21221020993829 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 21221021001986 and 21221021002004.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (21221021002091) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (23) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 248089566 + ... + 248175088.

It is an arithmetic number, because the mean of its divisors is an integer number (2653008360120).

Almost surely, 2^{21221021002021} is an apocalyptic number.

It is an amenable number.

21221021002021 is a deficient number, since it is larger than the sum of its proper divisors (3045878939).

21221021002021 is a wasteful number, since it uses less digits than its factorization.

21221021002021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 118235.

The product of its (nonzero) digits is 64, while the sum is 16.

Adding to 21221021002021 its reverse (12020012012212), we get a palindrome (33241033014233).

The spelling of 21221021002021 in words is "twenty-one trillion, two hundred twenty-one billion, twenty-one million, two thousand, twenty-one".