55055921 has 2 divisors, whose sum is σ = 55055922. Its totient is φ = 55055920.

The previous prime is 55055893. The next prime is 55055981. The reversal of 55055921 is 12955055.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 52128400 + 2927521 = 7220^2 + 1711^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-55055921 is a prime.

It is not a weakly prime, because it can be changed into another prime (55055981) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27527960 + 27527961.

It is an arithmetic number, because the mean of its divisors is an integer number (27527961).

Almost surely, 2^55055921 is an apocalyptic number.

It is an amenable number.

55055921 is a deficient number, since it is larger than the sum of its proper divisors (1).

55055921 is an equidigital number, since it uses as much as digits as its factorization.

55055921 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11250, while the sum is 32.

The square root of 55055921 is about 7419.9677223018. The cubic root of 55055921 is about 380.4240902397.

It can be divided in two parts, 5 and 5055921, that multiplied together give a triangular number (25279605 = T₇₁₁₀).

The spelling of 55055921 in words is "fifty-five million, fifty-five thousand, nine hundred twenty-one".