2555551 has 2 divisors, whose sum is σ = 2555552. Its totient is φ = 2555550.

The previous prime is 2555549. The next prime is 2555561. The reversal of 2555551 is 1555552.

It is a happy number.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 2555551 - 2¹ = 2555549 is a prime.

Together with 2555549, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (2555521) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 1277775 + 1277776.

It is an arithmetic number, because the mean of its divisors is an integer number (1277776).

2^2555551 is an apocalyptic number.

2555551 is a deficient number, since it is larger than the sum of its proper divisors (1).

2555551 is an equidigital number, since it uses as much as digits as its factorization.

2555551 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6250, while the sum is 28.

The square root of 2555551 is about 1598.6090829218. The cubic root of 2555551 is about 136.7187830846.

Subtracting from 2555551 its reverse (1555552), we obtain a palindrome (999999).

It can be divided in two parts, 25555 and 51, that multiplied together give a triangular number (1303305 = T₁₆₁₄).

The spelling of 2555551 in words is "two million, five hundred fifty-five thousand, five hundred fifty-one".