55436020021 has 2 divisors, whose sum is σ = 55436020022. Its totient is φ = 55436020020.

The previous prime is 55436020019. The next prime is 55436020063. The reversal of 55436020021 is 12002063455.

55436020021 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 33260640625 + 22175379396 = 182375^2 + 148914^2 .

It is a cyclic number.

It is not a de Polignac number, because 55436020021 - 2¹ = 55436020019 is a prime.

Together with 55436020019, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (55436020121) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 27718010010 + 27718010011.

It is an arithmetic number, because the mean of its divisors is an integer number (27718010011).

Almost surely, 2^55436020021 is an apocalyptic number.

It is an amenable number.

55436020021 is a deficient number, since it is larger than the sum of its proper divisors (1).

55436020021 is an equidigital number, since it uses as much as digits as its factorization.

55436020021 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 7200, while the sum is 28.

Adding to 55436020021 its reverse (12002063455), we get a palindrome (67438083476).

The spelling of 55436020021 in words is "fifty-five billion, four hundred thirty-six million, twenty thousand, twenty-one".