20400311123 has 16 divisors (see below), whose sum is σ = 20748752640. Its totient is φ = 20054632416.

The previous prime is 20400311111. The next prime is 20400311167. The reversal of 20400311123 is 32111300402.

It is a cyclic number.

It is not a de Polignac number, because 20400311123 - 2⁸ = 20400310867 is a prime.

It is a super-2 number, since 2×20400311123² (a number of 21 digits) contains 22 as substring.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (20400311023) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24667436 + ... + 24668262.

It is an arithmetic number, because the mean of its divisors is an integer number (1296797040).

Almost surely, 2^20400311123 is an apocalyptic number.

20400311123 is a deficient number, since it is larger than the sum of its proper divisors (348441517).

20400311123 is an equidigital number, since it uses as much as digits as its factorization.

20400311123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2026.

The product of its (nonzero) digits is 144, while the sum is 17.

Adding to 20400311123 its reverse (32111300402), we get a palindrome (52511611525).

The spelling of 20400311123 in words is "twenty billion, four hundred million, three hundred eleven thousand, one hundred twenty-three".