55961 has 4 divisors (see below), whose sum is σ = 56592. Its totient is φ = 55332.

The previous prime is 55949. The next prime is 55967. The reversal of 55961 is 16955.

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 a brilliant number, because the two primes have the same length, and also an emirpimes, since its reverse is a distinct semiprime: 16955 = 5 ⋅3391.

It is a cyclic number.

It is not a de Polignac number, because 55961 - 2⁶ = 55897 is a prime.

It is a Duffinian number.

It is a plaindrome in base 15.

It is a nialpdrome in base 16.

It is a self number, because there is not a number n which added to its sum of digits gives 55961.

It is not an unprimeable number, because it can be changed into a prime (55967) 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, 155 + ... + 368.

It is an arithmetic number, because the mean of its divisors is an integer number (14148).

2⁵⁵⁹⁶¹ is an apocalyptic number.

It is an amenable number.

55961 is a deficient number, since it is larger than the sum of its proper divisors (631).

55961 is a wasteful number, since it uses less digits than its factorization.

55961 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 630.

The product of its digits is 1350, while the sum is 26.

The square root of 55961 is about 236.5607744323. The cubic root of 55961 is about 38.2497401267.

The spelling of 55961 in words is "fifty-five thousand, nine hundred sixty-one".