1021220020021 has 16 divisors (see below), whose sum is σ = 1092655987200. Its totient is φ = 952323825600.

The previous prime is 1021220020003. The next prime is 1021220020031. The reversal of 1021220020021 is 1200200221201.

It is a happy number.

It is a cyclic number.

It is not a de Polignac number, because 1021220020021 - 2⁹ = 1021220019509 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1021220019983 and 1021220020010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1021220020031) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 658275 + ... + 1573456.

It is an arithmetic number, because the mean of its divisors is an integer number (68290999200).

Almost surely, 2^{1021220020021} is an apocalyptic number.

It is an amenable number.

1021220020021 is a deficient number, since it is larger than the sum of its proper divisors (71435967179).

1021220020021 is a wasteful number, since it uses less digits than its factorization.

1021220020021 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2232300.

The product of its (nonzero) digits is 32, while the sum is 13.

Adding to 1021220020021 its reverse (1200200221201), we get a palindrome (2221420241222).

The spelling of 1021220020021 in words is "one trillion, twenty-one billion, two hundred twenty million, twenty thousand, twenty-one".