55577684821 has 2 divisors, whose sum is σ = 55577684822. Its totient is φ = 55577684820.

The previous prime is 55577684717. The next prime is 55577684887. The reversal of 55577684821 is 12848677555.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 38932814596 + 16644870225 = 197314^2 + 129015^2 .

It is a cyclic number.

It is not a de Polignac number, because 55577684821 - 2⁷ = 55577684693 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55577684891) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27788842410 + 27788842411.

It is an arithmetic number, because the mean of its divisors is an integer number (27788842411).

Almost surely, 2^55577684821 is an apocalyptic number.

It is an amenable number.

55577684821 is a deficient number, since it is larger than the sum of its proper divisors (1).

55577684821 is an equidigital number, since it uses as much as digits as its factorization.

55577684821 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18816000, while the sum is 58.

The spelling of 55577684821 in words is "fifty-five billion, five hundred seventy-seven million, six hundred eighty-four thousand, eight hundred twenty-one".