55321909 has 2 divisors, whose sum is σ = 55321910. Its totient is φ = 55321908.

The previous prime is 55321897. The next prime is 55321991. The reversal of 55321909 is 90912355.

It is a happy number.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 53333809 + 1988100 = 7303^2 + 1410^2 .

It is a cyclic number.

It is not a de Polignac number, because 55321909 - 2⁷ = 55321781 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55321109) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27660954 + 27660955.

It is an arithmetic number, because the mean of its divisors is an integer number (27660955).

Almost surely, 2^55321909 is an apocalyptic number.

It is an amenable number.

55321909 is a deficient number, since it is larger than the sum of its proper divisors (1).

55321909 is an equidigital number, since it uses as much as digits as its factorization.

55321909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 12150, while the sum is 34.

The square root of 55321909 is about 7437.8699235735. The cubic root of 55321909 is about 381.0357454585.

The spelling of 55321909 in words is "fifty-five million, three hundred twenty-one thousand, nine hundred nine".