20213111 has 4 divisors (see below), whose sum is σ = 20233224. Its totient is φ = 20193000.

The previous prime is 20213107. The next prime is 20213183. The reversal of 20213111 is 11131202.

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 20213111 - 2² = 20213107 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20213092 and 20213101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20213411) 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, 8465 + ... + 10586.

It is an arithmetic number, because the mean of its divisors is an integer number (5058306).

Almost surely, 2^20213111 is an apocalyptic number.

20213111 is a deficient number, since it is larger than the sum of its proper divisors (20113).

20213111 is a wasteful number, since it uses less digits than its factorization.

20213111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 20112.

The product of its (nonzero) digits is 12, while the sum is 11.

The square root of 20213111 is about 4495.8993538557. The cubic root of 20213111 is about 272.4024777983.

Adding to 20213111 its reverse (11131202), we get a palindrome (31344313).

The spelling of 20213111 in words is "twenty million, two hundred thirteen thousand, one hundred eleven".