12555551 has 2 divisors, whose sum is σ = 12555552. Its totient is φ = 12555550.

The previous prime is 12555547. The next prime is 12555577. The reversal of 12555551 is 15555521.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 12555551 - 2² = 12555547 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12555511) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6277775 + 6277776.

It is an arithmetic number, because the mean of its divisors is an integer number (6277776).

Almost surely, 2^12555551 is an apocalyptic number.

12555551 is a deficient number, since it is larger than the sum of its proper divisors (1).

12555551 is an equidigital number, since it uses as much as digits as its factorization.

12555551 is an evil number, because the sum of its binary digits is even.

The product of its digits is 6250, while the sum is 29.

The square root of 12555551 is about 3543.3812947522. The cubic root of 12555551 is about 232.4227268545.

It can be divided in two parts, 1 and 2555551, that added together give a palindrome (2555552).

The spelling of 12555551 in words is "twelve million, five hundred fifty-five thousand, five hundred fifty-one".