1211000020001 has 4 divisors (see below), whose sum is σ = 1211002235412. Its totient is φ = 1210997804592.

The previous prime is 1211000019997. The next prime is 1211000020007. The reversal of 1211000020001 is 1000200001121.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 1170929589025 + 40070430976 = 1082095^2 + 200176^2 .

It is a cyclic number.

It is not a de Polignac number, because 1211000020001 - 2² = 1211000019997 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1211000020007) 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, 364055 + ... + 1598291.

It is an arithmetic number, because the mean of its divisors is an integer number (302750558853).

Almost surely, 2^{1211000020001} is an apocalyptic number.

It is an amenable number.

1211000020001 is a deficient number, since it is larger than the sum of its proper divisors (2215411).

1211000020001 is an equidigital number, since it uses as much as digits as its factorization.

1211000020001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 2215410.

The product of its (nonzero) digits is 4, while the sum is 8.

Adding to 1211000020001 its reverse (1000200001121), we get a palindrome (2211200021122).

The spelling of 1211000020001 in words is "one trillion, two hundred eleven billion, twenty thousand, one".