51553 has 4 divisors (see below), whose sum is σ = 53248. Its totient is φ = 49860.

The previous prime is 51551. The next prime is 51563. The reversal of 51553 is 35515.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 35515 = 5 ⋅7103.

It is a cyclic number.

It is not a de Polignac number, because 51553 - 2¹ = 51551 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 9 and base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 51553.

It is not an unprimeable number, because it can be changed into a prime (51551) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (7) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 801 + ... + 862.

It is an arithmetic number, because the mean of its divisors is an integer number (13312).

2⁵¹⁵⁵³ is an apocalyptic number.

It is an amenable number.

51553 is a deficient number, since it is larger than the sum of its proper divisors (1695).

51553 is a wasteful number, since it uses less digits than its factorization.

51553 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1694.

The product of its digits is 375, while the sum is 19.

The square root of 51553 is about 227.0528572822. The cubic root of 51553 is about 37.2178528406.

It can be divided in two parts, 51 and 553, that multiplied together give a triangular number (28203 = T₂₃₇).

The spelling of 51553 in words is "fifty-one thousand, five hundred fifty-three".