20001031123 has 4 divisors (see below), whose sum is σ = 20008477440. Its totient is φ = 19993584808.

The previous prime is 20001031069. The next prime is 20001031139. The reversal of 20001031123 is 32113010002.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-20001031123 is a prime.

It is a super-2 number, since 2×20001031123² (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 (20001031723) 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, 3719128 + ... + 3724501.

It is an arithmetic number, because the mean of its divisors is an integer number (5002119360).

Almost surely, 2^20001031123 is an apocalyptic number.

20001031123 is a deficient number, since it is larger than the sum of its proper divisors (7446317).

20001031123 is an equidigital number, since it uses as much as digits as its factorization.

20001031123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 7446316.

The product of its (nonzero) digits is 36, while the sum is 13.

Adding to 20001031123 its reverse (32113010002), we get a palindrome (52114041125).

The spelling of 20001031123 in words is "twenty billion, one million, thirty-one thousand, one hundred twenty-three".