2105123531 has 8 divisors (see below), whose sum is σ = 2406343680. Its totient is φ = 1804025448.

The previous prime is 2105123519. The next prime is 2105123533. The reversal of 2105123531 is 1353215012.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-2105123531 is a prime.

It is a super-2 number, since 2×2105123531² = 8863090161539815922, which contains 22 as substring.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 2105123497 and 2105123506.

It is not an unprimeable number, because it can be changed into a prime (2105123533) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 10040 + ... + 65658.

It is an arithmetic number, because the mean of its divisors is an integer number (300792960).

Almost surely, 2^2105123531 is an apocalyptic number.

2105123531 is a deficient number, since it is larger than the sum of its proper divisors (301220149).

2105123531 is an equidigital number, since it uses as much as digits as its factorization.

2105123531 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 61033.

The product of its (nonzero) digits is 900, while the sum is 23.

The square root of 2105123531 is about 45881.6252000733. The cubic root of 2105123531 is about 1281.6197615602.

Adding to 2105123531 its reverse (1353215012), we get a palindrome (3458338543).

The spelling of 2105123531 in words is "two billion, one hundred five million, one hundred twenty-three thousand, five hundred thirty-one".