1628195561 has 2 divisors, whose sum is σ = 1628195562. Its totient is φ = 1628195560.

The previous prime is 1628195549. The next prime is 1628195579. The reversal of 1628195561 is 1655918261.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1617567961 + 10627600 = 40219^2 + 3260^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1628195561 is a prime.

It is not a weakly prime, because it can be changed into another prime (1628195521) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 814097780 + 814097781.

It is an arithmetic number, because the mean of its divisors is an integer number (814097781).

Almost surely, 2^1628195561 is an apocalyptic number.

It is an amenable number.

1628195561 is a deficient number, since it is larger than the sum of its proper divisors (1).

1628195561 is an equidigital number, since it uses as much as digits as its factorization.

1628195561 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 129600, while the sum is 44.

The square root of 1628195561 is about 40350.9053306119. The cubic root of 1628195561 is about 1176.4374888331.

The spelling of 1628195561 in words is "one billion, six hundred twenty-eight million, one hundred ninety-five thousand, five hundred sixty-one".