55047821 has 2 divisors, whose sum is σ = 55047822. Its totient is φ = 55047820.

The previous prime is 55047799. The next prime is 55047827. The reversal of 55047821 is 12874055.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 33988900 + 21058921 = 5830^2 + 4589^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-55047821 is a prime.

It is a Chen prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55047827) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27523910 + 27523911.

It is an arithmetic number, because the mean of its divisors is an integer number (27523911).

Almost surely, 2^55047821 is an apocalyptic number.

It is an amenable number.

55047821 is a deficient number, since it is larger than the sum of its proper divisors (1).

55047821 is an equidigital number, since it uses as much as digits as its factorization.

55047821 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11200, while the sum is 32.

The square root of 55047821 is about 7419.4218777476. The cubic root of 55047821 is about 380.4054329291.

The spelling of 55047821 in words is "fifty-five million, forty-seven thousand, eight hundred twenty-one".