20812123 has 2 divisors, whose sum is σ = 20812124. Its totient is φ = 20812122.

The previous prime is 20812091. The next prime is 20812139. The reversal of 20812123 is 32121802.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20812123 - 2⁵ = 20812091 is a prime.

It is a self number, because there is not a number n which added to its sum of digits gives 20812123.

It is not a weakly prime, because it can be changed into another prime (20812153) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10406061 + 10406062.

It is an arithmetic number, because the mean of its divisors is an integer number (10406062).

Almost surely, 2^20812123 is an apocalyptic number.

20812123 is a deficient number, since it is larger than the sum of its proper divisors (1).

20812123 is an equidigital number, since it uses as much as digits as its factorization.

20812123 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 192, while the sum is 19.

The square root of 20812123 is about 4562.0305785911. The cubic root of 20812123 is about 275.0671923966.

Adding to 20812123 its reverse (32121802), we get a palindrome (52933925).

The spelling of 20812123 in words is "twenty million, eight hundred twelve thousand, one hundred twenty-three".