20001000123 has 96 divisors (see below), whose sum is σ = 36185909760. Its totient is φ = 10496977920.

The previous prime is 20001000109. The next prime is 20001000181. The reversal of 20001000123 is 32100010002.

It is a happy number.

It is not a de Polignac number, because 20001000123 - 2¹³ = 20000991931 is a prime.

It is a Harshad number since it is a multiple of its sum of digits (9).

It is not an unprimeable number, because it can be changed into a prime (20003000123) by changing a digit.

It is a polite number, since it can be written in 95 ways as a sum of consecutive naturals, for example, 857688 + ... + 880698.

It is an arithmetic number, because the mean of its divisors is an integer number (376936560).

Almost surely, 2^20001000123 is an apocalyptic number.

20001000123 is a gapful number since it is divisible by the number (23) formed by its first and last digit.

20001000123 is a deficient number, since it is larger than the sum of its proper divisors (16184909637).

20001000123 is a wasteful number, since it uses less digits than its factorization.

20001000123 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 23089 (or 23086 counting only the distinct ones).

The product of its (nonzero) digits is 12, while the sum is 9.

Adding to 20001000123 its reverse (32100010002), we get a palindrome (52101010125).

The spelling of 20001000123 in words is "twenty billion, one million, one hundred twenty-three", and thus it is an aban number.