63551 has 4 divisors (see below), whose sum is σ = 64272. Its totient is φ = 62832.

The previous prime is 63541. The next prime is 63559. The reversal of 63551 is 15536.

It is a semiprime because it is the product of two primes, and also a brilliant number, because the two primes have the same length.

It is a cyclic number.

It is not a de Polignac number, because 63551 - 2⁶ = 63487 is a prime.

It is a zygodrome in base 2.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (63559) 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 in 3 ways as a sum of consecutive naturals, for example, 206 + ... + 411.

It is an arithmetic number, because the mean of its divisors is an integer number (16068).

2⁶³⁵⁵¹ is an apocalyptic number.

63551 is the 206-th pentagonal number.

63551 is a deficient number, since it is larger than the sum of its proper divisors (721).

63551 is a wasteful number, since it uses less digits than its factorization.

63551 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 720.

The product of its digits is 450, while the sum is 20.

The square root of 63551 is about 252.0932367201. The cubic root of 63551 is about 39.9062387256.

It can be divided in two parts, 635 and 51, that multiplied together give a triangular number (32385 = T₂₅₄).

The spelling of 63551 in words is "sixty-three thousand, five hundred fifty-one".