20001211 has 4 divisors (see below), whose sum is σ = 20154024. Its totient is φ = 19848400.

The previous prime is 20001203. The next prime is 20001217. The reversal of 20001211 is 11210002.

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

It is a cyclic number.

It is not a de Polignac number, because 20001211 - 2³ = 20001203 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20001194 and 20001203.

It is not an unprimeable number, because it can be changed into a prime (20001217) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 76210 + ... + 76471.

It is an arithmetic number, because the mean of its divisors is an integer number (5038506).

Almost surely, 2^20001211 is an apocalyptic number.

20001211 is a deficient number, since it is larger than the sum of its proper divisors (152813).

20001211 is a wasteful number, since it uses less digits than its factorization.

20001211 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 152812.

The product of its (nonzero) digits is 4, while the sum is 7.

The square root of 20001211 is about 4472.2713468662. The cubic root of 20001211 is about 271.4472401485.

Adding to 20001211 its reverse (11210002), we get a palindrome (31211213).

The spelling of 20001211 in words is "twenty million, one thousand, two hundred eleven".