1211121201001 has 8 divisors (see below), whose sum is σ = 1218217539080. Its totient is φ = 1204040581632.

The previous prime is 1211121200987. The next prime is 1211121201053. The reversal of 1211121201001 is 1001021211121.

It is a happy number.

It can be written as a sum of positive squares in 4 ways, for example, as 560138483776 + 650982717225 = 748424^2 + 806835^2 .

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 1211121201001 - 2¹⁹ = 1211120676713 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1211121201091) 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, 3775110 + ... + 4083343.

It is an arithmetic number, because the mean of its divisors is an integer number (152277192385).

Almost surely, 2^{1211121201001} is an apocalyptic number.

It is an amenable number.

1211121201001 is a deficient number, since it is larger than the sum of its proper divisors (7096338079).

1211121201001 is an equidigital number, since it uses as much as digits as its factorization.

1211121201001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7859355.

The product of its (nonzero) digits is 8, while the sum is 13.

Adding to 1211121201001 its reverse (1001021211121), we get a palindrome (2212142412122).

The spelling of 1211121201001 in words is "one trillion, two hundred eleven billion, one hundred twenty-one million, two hundred one thousand, one".