1221102021001 has 4 divisors (see below), whose sum is σ = 1229188789504. Its totient is φ = 1213015252500.

The previous prime is 1221102020977. The next prime is 1221102021011. The reversal of 1221102021001 is 1001202011221.

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 a de Polignac number, because none of the positive numbers 2^k-1221102021001 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221102021011) 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 3 ways as a sum of consecutive naturals, for example, 4043384025 + ... + 4043384326.

It is an arithmetic number, because the mean of its divisors is an integer number (307297197376).

Almost surely, 2^{1221102021001} is an apocalyptic number.

It is an amenable number.

1221102021001 is a deficient number, since it is larger than the sum of its proper divisors (8086768503).

1221102021001 is an equidigital number, since it uses as much as digits as its factorization.

1221102021001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 8086768502.

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

Adding to 1221102021001 its reverse (1001202011221), we get a palindrome (2222304032222).

The spelling of 1221102021001 in words is "one trillion, two hundred twenty-one billion, one hundred two million, twenty-one thousand, one".