20123111 has 4 divisors (see below), whose sum is σ = 20167224. Its totient is φ = 20079000.

The previous prime is 20123099. The next prime is 20123119. The reversal of 20123111 is 11132102.

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 20123111 - 2¹⁰ = 20122087 is a prime.

It is a super-3 number, since 3×20123111³ (a number of 23 digits) contains 333 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 20123092 and 20123101.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20123119) 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, 21365 + ... + 22286.

It is an arithmetic number, because the mean of its divisors is an integer number (5041806).

Almost surely, 2^20123111 is an apocalyptic number.

20123111 is a deficient number, since it is larger than the sum of its proper divisors (44113).

20123111 is an equidigital number, since it uses as much as digits as its factorization.

20123111 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 44112.

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

The square root of 20123111 is about 4485.8790665822. The cubic root of 20123111 is about 271.9975805364.

Adding to 20123111 its reverse (11132102), we get a palindrome (31255213).

The spelling of 20123111 in words is "twenty million, one hundred twenty-three thousand, one hundred eleven".