61644021133 has 2 divisors, whose sum is σ = 61644021134. Its totient is φ = 61644021132.

The previous prime is 61644021121. The next prime is 61644021163. The reversal of 61644021133 is 33112044616.

It is a happy number.

61644021133 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., 46028269764 + 15615751369 = 214542^2 + 124963^2 .

It is a cyclic number.

It is not a de Polignac number, because 61644021133 - 2⁹ = 61644020621 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 61644021095 and 61644021104.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (61644021163) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 30822010566 + 30822010567.

It is an arithmetic number, because the mean of its divisors is an integer number (30822010567).

Almost surely, 2^61644021133 is an apocalyptic number.

It is an amenable number.

61644021133 is a deficient number, since it is larger than the sum of its proper divisors (1).

61644021133 is an equidigital number, since it uses as much as digits as its factorization.

61644021133 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 10368, while the sum is 31.

Adding to 61644021133 its reverse (33112044616), we get a palindrome (94756065749).

The spelling of 61644021133 in words is "sixty-one billion, six hundred forty-four million, twenty-one thousand, one hundred thirty-three".