1021021001221 has 16 divisors (see below), whose sum is σ = 1126357133440. Its totient is φ = 919560600000.

The previous prime is 1021021001219. The next prime is 1021021001233. The reversal of 1021021001221 is 1221001201201.

It is a cyclic number.

It is not a de Polignac number, because 1021021001221 - 2¹ = 1021021001219 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (13).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1021021001621) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 480030 + ... + 1507471.

It is an arithmetic number, because the mean of its divisors is an integer number (70397320840).

Almost surely, 2^{1021021001221} is an apocalyptic number.

It is an amenable number.

1021021001221 is a deficient number, since it is larger than the sum of its proper divisors (105336132219).

1021021001221 is a wasteful number, since it uses less digits than its factorization.

1021021001221 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1988476.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 1021021001221 its reverse (1221001201201), we get a palindrome (2242022202422).

The spelling of 1021021001221 in words is "one trillion, twenty-one billion, twenty-one million, one thousand, two hundred twenty-one".