1211221210001 has 8 divisors (see below), whose sum is σ = 1321341857184. Its totient is φ = 1101102167520.

The previous prime is 1211221209943. The next prime is 1211221210019. The reversal of 1211221210001 is 1000121221121.

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 1211221210001 - 2³⁸ = 936343303057 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1211221210061) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1619645 + ... + 2246261.

It is an arithmetic number, because the mean of its divisors is an integer number (165167732148).

Almost surely, 2^{1211221210001} is an apocalyptic number.

1211221210001 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1211221210001 is a deficient number, since it is larger than the sum of its proper divisors (110120647183).

1211221210001 is a wasteful number, since it uses less digits than its factorization.

1211221210001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 802351.

The product of its (nonzero) digits is 16, while the sum is 14.

Adding to 1211221210001 its reverse (1000121221121), we get a palindrome (2211342431122).

The spelling of 1211221210001 in words is "one trillion, two hundred eleven billion, two hundred twenty-one million, two hundred ten thousand, one".