215123123 has 2 divisors, whose sum is σ = 215123124. Its totient is φ = 215123122.

The previous prime is 215123101. The next prime is 215123137. The reversal of 215123123 is 321321512.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 215123123 - 2⁸ = 215122867 is a prime.

It is a Sophie Germain prime.

It is a junction number, because it is equal to n+sod(n) for n = 215123095 and 215123104.

It is not a weakly prime, because it can be changed into another prime (215123723) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 107561561 + 107561562.

It is an arithmetic number, because the mean of its divisors is an integer number (107561562).

Almost surely, 2^215123123 is an apocalyptic number.

215123123 is a deficient number, since it is larger than the sum of its proper divisors (1).

215123123 is an equidigital number, since it uses as much as digits as its factorization.

215123123 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 360, while the sum is 20.

The square root of 215123123 is about 14667.0761571623. The cubic root of 215123123 is about 599.1869756685.

Adding to 215123123 its reverse (321321512), we get a palindrome (536444635).

The spelling of 215123123 in words is "two hundred fifteen million, one hundred twenty-three thousand, one hundred twenty-three".