15551 has 2 divisors, whose sum is σ = 15552. Its totient is φ = 15550.

The previous prime is 15541. The next prime is 15559.

15551 is nontrivially palindromic in base 10.

It is a strong prime.

It is a palprime.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-15551 is a prime.

It is a Chen prime.

It is a plaindrome in base 6 and base 12.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (15559) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 7775 + 7776.

It is an arithmetic number, because the mean of its divisors is an integer number (7776).

2¹⁵⁵⁵¹ is an apocalyptic number.

15551 is a deficient number, since it is larger than the sum of its proper divisors (1).

15551 is an equidigital number, since it uses as much as digits as its factorization.

15551 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 125, while the sum is 17.

The square root of 15551 is about 124.7036487036. The cubic root of 15551 is about 24.9604708642.

The spelling of 15551 in words is "fifteen thousand, five hundred fifty-one".