20321111 has 4 divisors (see below), whose sum is σ = 20330424. Its totient is φ = 20311800.

The previous prime is 20321087. The next prime is 20321131. The reversal of 20321111 is 11112302.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20321111 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20321092 and 20321101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20321131) 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, 581 + ... + 6401.

It is an arithmetic number, because the mean of its divisors is an integer number (5082606).

Almost surely, 2^20321111 is an apocalyptic number.

20321111 is a deficient number, since it is larger than the sum of its proper divisors (9313).

20321111 is an equidigital number, since it uses as much as digits as its factorization.

20321111 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 9312.

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

The square root of 20321111 is about 4507.8942977847. The cubic root of 20321111 is about 272.8867711506.

Adding to 20321111 its reverse (11112302), we get a palindrome (31433413).

The spelling of 20321111 in words is "twenty million, three hundred twenty-one thousand, one hundred eleven".