1002100001221 has 16 divisors (see below), whose sum is σ = 1143922963968. Its totient is φ = 869535993600.

The previous prime is 1002100001219. The next prime is 1002100001263. The reversal of 1002100001221 is 1221000012001.

It is a cyclic number.

It is not a de Polignac number, because 1002100001221 - 2¹ = 1002100001219 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1002100001198 and 1002100001207.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1002100001321) 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, 20103256 + ... + 20153041.

It is an arithmetic number, because the mean of its divisors is an integer number (71495185248).

Almost surely, 2^{1002100001221} is an apocalyptic number.

1002100001221 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1002100001221 is a deficient number, since it is larger than the sum of its proper divisors (141822962747).

1002100001221 is a wasteful number, since it uses less digits than its factorization.

1002100001221 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 40256412.

The product of its (nonzero) digits is 8, while the sum is 10.

Adding to 1002100001221 its reverse (1221000012001), we get a palindrome (2223100013222).

The spelling of 1002100001221 in words is "one trillion, two billion, one hundred million, one thousand, two hundred twenty-one".