55921 has 2 divisors, whose sum is σ = 55922. Its totient is φ = 55920.

The previous prime is 55903. The next prime is 55927. The reversal of 55921 is 12955.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 55696 + 225 = 236^2 + 15^2 .

It is a cyclic number.

It is not a de Polignac number, because 55921 - 2⁵ = 55889 is a prime.

It is a nialpdrome in base 16.

It is a junction number, because it is equal to n+sod(n) for n = 55892 and 55901.

It is not a weakly prime, because it can be changed into another prime (55927) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27960 + 27961.

It is an arithmetic number, because the mean of its divisors is an integer number (27961).

2⁵⁵⁹²¹ is an apocalyptic number.

It is an amenable number.

55921 is a deficient number, since it is larger than the sum of its proper divisors (1).

55921 is an equidigital number, since it uses as much as digits as its factorization.

55921 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 450, while the sum is 22.

The square root of 55921 is about 236.4762144487. The cubic root of 55921 is about 38.2406245266.

The spelling of 55921 in words is "fifty-five thousand, nine hundred twenty-one".