1221021100001 has 8 divisors (see below), whose sum is σ = 1226608032000. Its totient is φ = 1215436385520.

The previous prime is 1221021099997. The next prime is 1221021100009. The reversal of 1221021100001 is 1000011201221.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is not a de Polignac number, because 1221021100001 - 2² = 1221021099997 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1221021100009) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 554450 + ... + 1658148.

It is an arithmetic number, because the mean of its divisors is an integer number (153326004000).

Almost surely, 2^{1221021100001} is an apocalyptic number.

It is an amenable number.

1221021100001 is a deficient number, since it is larger than the sum of its proper divisors (5586931999).

1221021100001 is a wasteful number, since it uses less digits than its factorization.

1221021100001 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1108759.

The product of its (nonzero) digits is 8, while the sum is 11.

Adding to 1221021100001 its reverse (1000011201221), we get a palindrome (2221032301222).

The spelling of 1221021100001 in words is "one trillion, two hundred twenty-one billion, twenty-one million, one hundred thousand, one".