20400124123 has 4 divisors (see below), whose sum is σ = 20897688168. Its totient is φ = 19902560080.

The previous prime is 20400124103. The next prime is 20400124133. The reversal of 20400124123 is 32142100402.

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 20400124123 - 2¹⁷ = 20399993051 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 20400124123.

It is not an unprimeable number, because it can be changed into a prime (20400124103) 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, 248781961 + ... + 248782042.

It is an arithmetic number, because the mean of its divisors is an integer number (5224422042).

Almost surely, 2^20400124123 is an apocalyptic number.

20400124123 is a deficient number, since it is larger than the sum of its proper divisors (497564045).

20400124123 is an equidigital number, since it uses as much as digits as its factorization.

20400124123 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 497564044.

The product of its (nonzero) digits is 384, while the sum is 19.

Adding to 20400124123 its reverse (32142100402), we get a palindrome (52542224525).

The spelling of 20400124123 in words is "twenty billion, four hundred million, one hundred twenty-four thousand, one hundred twenty-three".