2001211210021 has 16 divisors (see below), whose sum is σ = 2032670050560. Its totient is φ = 1969998508800.

The previous prime is 2001211210001. The next prime is 2001211210087. The reversal of 2001211210021 is 1200121121002.

It is a cyclic number.

It is not a de Polignac number, because 2001211210021 - 2³⁵ = 1966851471653 is a prime.

It is a super-2 number, since 2×2001211210021² (a number of 25 digits) contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2001211209983 and 2001211210010.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2001211210001) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 161733991 + ... + 161746363.

It is an arithmetic number, because the mean of its divisors is an integer number (127041878160).

Almost surely, 2^{2001211210021} is an apocalyptic number.

It is an amenable number.

2001211210021 is a deficient number, since it is larger than the sum of its proper divisors (31458840539).

2001211210021 is a wasteful number, since it uses less digits than its factorization.

2001211210021 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 22116.

The product of its (nonzero) digits is 16, while the sum is 13.

Adding to 2001211210021 its reverse (1200121121002), we get a palindrome (3201332331023).

The spelling of 2001211210021 in words is "two trillion, one billion, two hundred eleven million, two hundred ten thousand, twenty-one".