2155511 has 2 divisors, whose sum is σ = 2155512. Its totient is φ = 2155510.

The previous prime is 2155499. The next prime is 2155513. The reversal of 2155511 is 1155512.

It is a happy number.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 2155511 - 2¹⁰ = 2154487 is a prime.

It is a super-2 number, since 2×2155511² = 9292455342242, which contains 22 as substring.

Together with 2155513, it forms a pair of twin primes.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2155513) 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, 1077755 + 1077756.

It is an arithmetic number, because the mean of its divisors is an integer number (1077756).

2^2155511 is an apocalyptic number.

2155511 is a deficient number, since it is larger than the sum of its proper divisors (1).

2155511 is an equidigital number, since it uses as much as digits as its factorization.

2155511 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 250, while the sum is 20.

The square root of 2155511 is about 1468.1658625646. The cubic root of 2155511 is about 129.1764706167.

Subtracting from 2155511 its reverse (1155512), we obtain a palindrome (999999).

The spelling of 2155511 in words is "two million, one hundred fifty-five thousand, five hundred eleven".