1906560661 has 2 divisors, whose sum is σ = 1906560662. Its totient is φ = 1906560660.

The previous prime is 1906560631. The next prime is 1906560701. The reversal of 1906560661 is 1660656091.

It is an a-pointer prime, because the next prime (1906560701) can be obtained adding 1906560661 to its sum of digits (40).

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 1586508561 + 320052100 = 39831^2 + 17890^2 .

It is an emirp because it is prime and its reverse (1660656091) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 1906560661 - 2⁵ = 1906560629 is a prime.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (1906560611) 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, 953280330 + 953280331.

It is an arithmetic number, because the mean of its divisors is an integer number (953280331).

Almost surely, 2^1906560661 is an apocalyptic number.

It is an amenable number.

1906560661 is a deficient number, since it is larger than the sum of its proper divisors (1).

1906560661 is an equidigital number, since it uses as much as digits as its factorization.

1906560661 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 58320, while the sum is 40.

The square root of 1906560661 is about 43664.1805259185. The cubic root of 1906560661 is about 1239.9862687085.

The spelling of 1906560661 in words is "one billion, nine hundred six million, five hundred sixty thousand, six hundred sixty-one".