13005551 has 4 divisors (see below), whose sum is σ = 14005992. Its totient is φ = 12005112.

The previous prime is 13005539. The next prime is 13005563. The reversal of 13005551 is 15550031.

It is a happy number.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 15550031 = 7 ⋅2221433.

It is an interprime number because it is at equal distance from previous prime (13005539) and next prime (13005563).

It is a cyclic number.

It is not a de Polignac number, because 13005551 - 2¹⁰ = 13004527 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (13005521) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 500201 + ... + 500226.

It is an arithmetic number, because the mean of its divisors is an integer number (3501498).

Almost surely, 2^13005551 is an apocalyptic number.

13005551 is a deficient number, since it is larger than the sum of its proper divisors (1000441).

13005551 is a wasteful number, since it uses less digits than its factorization.

13005551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1000440.

The product of its (nonzero) digits is 375, while the sum is 20.

The square root of 13005551 is about 3606.3209785043. The cubic root of 13005551 is about 235.1669313401.

Adding to 13005551 its reverse (15550031), we get a palindrome (28555582).

The spelling of 13005551 in words is "thirteen million, five thousand, five hundred fifty-one".