55038821 has 2 divisors, whose sum is σ = 55038822. Its totient is φ = 55038820.

The previous prime is 55038817. The next prime is 55038827. The reversal of 55038821 is 12883055.

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., 44702596 + 10336225 = 6686^2 + 3215^2 .

It is a cyclic number.

It is not a de Polignac number, because 55038821 - 2² = 55038817 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55038827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27519410 + 27519411.

It is an arithmetic number, because the mean of its divisors is an integer number (27519411).

Almost surely, 2^55038821 is an apocalyptic number.

It is an amenable number.

55038821 is a deficient number, since it is larger than the sum of its proper divisors (1).

55038821 is an equidigital number, since it uses as much as digits as its factorization.

55038821 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 9600, while the sum is 32.

The square root of 55038821 is about 7418.8153366963. The cubic root of 55038821 is about 380.3847004373.

The spelling of 55038821 in words is "fifty-five million, thirty-eight thousand, eight hundred twenty-one".