12905551 has 4 divisors (see below), whose sum is σ = 13350600. Its totient is φ = 12460504.

The previous prime is 12905549. The next prime is 12905573. The reversal of 12905551 is 15550921.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 12905551 - 2¹ = 12905549 is a prime.

It is a super-2 number, since 2×12905551² = 333106493227202, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (12905521) 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 in 3 ways as a sum of consecutive naturals, for example, 222481 + ... + 222538.

It is an arithmetic number, because the mean of its divisors is an integer number (3337650).

Almost surely, 2^12905551 is an apocalyptic number.

12905551 is a deficient number, since it is larger than the sum of its proper divisors (445049).

12905551 is an equidigital number, since it uses as much as digits as its factorization.

12905551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 445048.

The product of its (nonzero) digits is 2250, while the sum is 28.

The square root of 12905551 is about 3592.4296792004. The cubic root of 12905551 is about 234.5626451291.

It can be divided in two parts, 12905 and 551, that added together give a square (13456 = 116²).

The spelling of 12905551 in words is "twelve million, nine hundred five thousand, five hundred fifty-one".