1221000202101 has 4 divisors (see below), whose sum is σ = 1628000269472. Its totient is φ = 814000134732.

The previous prime is 1221000202087. The next prime is 1221000202129. The reversal of 1221000202101 is 1012020001221.

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 not a de Polignac number, because 1221000202101 - 2¹⁰ = 1221000201077 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1221000202141) 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, 203500033681 + ... + 203500033686.

It is an arithmetic number, because the mean of its divisors is an integer number (407000067368).

Almost surely, 2^{1221000202101} is an apocalyptic number.

It is an amenable number.

1221000202101 is a deficient number, since it is larger than the sum of its proper divisors (407000067371).

1221000202101 is an equidigital number, since it uses as much as digits as its factorization.

1221000202101 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 407000067370.

The product of its (nonzero) digits is 16, while the sum is 12.

Adding to 1221000202101 its reverse (1012020001221), we get a palindrome (2233020203322).

The spelling of 1221000202101 in words is "one trillion, two hundred twenty-one billion, two hundred two thousand, one hundred one".