1211210021001 has 16 divisors (see below), whose sum is σ = 1697165860544. Its totient is φ = 767378816064.

The previous prime is 1211210020991. The next prime is 1211210021009. The reversal of 1211210021001 is 1001200121121.

It is not a de Polignac number, because 1211210021001 - 2²² = 1211205826697 is a prime.

It is a super-2 number, since 2×1211210021001² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1211210021009) 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 15 ways as a sum of consecutive naturals, for example, 126876646 + ... + 126886191.

It is an arithmetic number, because the mean of its divisors is an integer number (106072866284).

Almost surely, 2^{1211210021001} is an apocalyptic number.

It is an amenable number.

1211210021001 is a deficient number, since it is larger than the sum of its proper divisors (485955839543).

1211210021001 is a wasteful number, since it uses less digits than its factorization.

1211210021001 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 253762920.

The product of its (nonzero) digits is 8, while the sum is 12.

Adding to 1211210021001 its reverse (1001200121121), we get a palindrome (2212410142122).

The spelling of 1211210021001 in words is "one trillion, two hundred eleven billion, two hundred ten million, twenty-one thousand, one".