1021002121221 has 4 divisors (see below), whose sum is σ = 1361336161632. Its totient is φ = 680668080812.

The previous prime is 1021002121169. The next prime is 1021002121229. The reversal of 1021002121221 is 1221212001201.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1021002121221 - 2¹⁰ = 1021002120197 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 1021002121221.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1021002121229) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 170167020201 + ... + 170167020206.

It is an arithmetic number, because the mean of its divisors is an integer number (340334040408).

Almost surely, 2^{1021002121221} is an apocalyptic number.

It is an amenable number.

1021002121221 is a deficient number, since it is larger than the sum of its proper divisors (340334040411).

1021002121221 is an equidigital number, since it uses as much as digits as its factorization.

1021002121221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 340334040410.

The product of its (nonzero) digits is 32, while the sum is 15.

Adding to 1021002121221 its reverse (1221212001201), we get a palindrome (2242214122422).

The spelling of 1021002121221 in words is "one trillion, twenty-one billion, two million, one hundred twenty-one thousand, two hundred twenty-one".