2155123331 has 2 divisors, whose sum is σ = 2155123332. Its totient is φ = 2155123330.

The previous prime is 2155123309. The next prime is 2155123339. The reversal of 2155123331 is 1333215512.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 2155123331 - 2¹⁸ = 2154861187 is a prime.

It is a super-2 number, since 2×2155123331² = 9289113143641071122, which contains 22 as substring.

It is a Sophie Germain prime.

It is a self number, because there is not a number n which added to its sum of digits gives 2155123331.

It is not a weakly prime, because it can be changed into another prime (2155123339) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1077561665 + 1077561666.

It is an arithmetic number, because the mean of its divisors is an integer number (1077561666).

Almost surely, 2^2155123331 is an apocalyptic number.

2155123331 is a deficient number, since it is larger than the sum of its proper divisors (1).

2155123331 is an equidigital number, since it uses as much as digits as its factorization.

2155123331 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 2700, while the sum is 26.

The square root of 2155123331 is about 46423.3059033930. The cubic root of 2155123331 is about 1291.6872601605.

Adding to 2155123331 its reverse (1333215512), we get a palindrome (3488338843).

The spelling of 2155123331 in words is "two billion, one hundred fifty-five million, one hundred twenty-three thousand, three hundred thirty-one".