20101023123 has 4 divisors (see below), whose sum is σ = 26801364168. Its totient is φ = 13400682080.

The previous prime is 20101023067. The next prime is 20101023139. The reversal of 20101023123 is 32132010102.

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 20101023123 - 2⁸ = 20101022867 is a prime.

It is a super-2 number, since 2×20101023123² (a number of 21 digits) contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (20101023823) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 3350170518 + ... + 3350170523.

It is an arithmetic number, because the mean of its divisors is an integer number (6700341042).

Almost surely, 2^20101023123 is an apocalyptic number.

20101023123 is a deficient number, since it is larger than the sum of its proper divisors (6700341045).

20101023123 is an equidigital number, since it uses as much as digits as its factorization.

20101023123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 6700341044.

The product of its (nonzero) digits is 72, while the sum is 15.

Adding to 20101023123 its reverse (32132010102), we get a palindrome (52233033225).

The spelling of 20101023123 in words is "twenty billion, one hundred one million, twenty-three thousand, one hundred twenty-three".