2100123456 has 28 divisors (see below), whose sum is σ = 5556577152. Its totient is φ = 700041088.

The previous prime is 2100123437. The next prime is 2100123457. The reversal of 2100123456 is 6543210012.

It is a Harshad number since it is a multiple of its sum of digits (24).

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2100123457) 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, 5468880 + ... + 5469263.

It is an arithmetic number, because the mean of its divisors is an integer number (198449184).

Almost surely, 2^2100123456 is an apocalyptic number.

It is an amenable number.

2100123456 is an abundant number, since it is smaller than the sum of its proper divisors (3456453696).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

2100123456 is a wasteful number, since it uses less digits than its factorization.

2100123456 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10938158 (or 10938148 counting only the distinct ones).

The product of its (nonzero) digits is 1440, while the sum is 24.

The square root of 2100123456 is about 45827.1039451546. The cubic root of 2100123456 is about 1280.6042589690.

Adding to 2100123456 its reverse (6543210012), we get a palindrome (8643333468).

The spelling of 2100123456 in words is "two billion, one hundred million, one hundred twenty-three thousand, four hundred fifty-six".