2155531123 has 2 divisors, whose sum is σ = 2155531124. Its totient is φ = 2155531122.

The previous prime is 2155531121. The next prime is 2155531129. The reversal of 2155531123 is 3211355512.

2155531123 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2155531123 - 2¹ = 2155531121 is a prime.

It is a super-2 number, since 2×2155531123² = 9292628844443282258, which contains 22 as substring.

Together with 2155531121, it forms a pair of twin primes.

It is a junction number, because it is equal to n+sod(n) for n = 2155531091 and 2155531100.

It is not a weakly prime, because it can be changed into another prime (2155531121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1077765561 + 1077765562.

It is an arithmetic number, because the mean of its divisors is an integer number (1077765562).

Almost surely, 2^2155531123 is an apocalyptic number.

2155531123 is a deficient number, since it is larger than the sum of its proper divisors (1).

2155531123 is an equidigital number, since it uses as much as digits as its factorization.

2155531123 is an evil number, because the sum of its binary digits is even.

The product of its digits is 4500, while the sum is 28.

The square root of 2155531123 is about 46427.6977999125. The cubic root of 2155531123 is about 1291.7687259563.

Adding to 2155531123 its reverse (3211355512), we get a palindrome (5366886635).

The spelling of 2155531123 in words is "two billion, one hundred fifty-five million, five hundred thirty-one thousand, one hundred twenty-three".