1909681801 has 2 divisors, whose sum is σ = 1909681802. Its totient is φ = 1909681800.

The previous prime is 1909681759. The next prime is 1909681843. The reversal of 1909681801 is 1081869091.

1909681801 = 30900² + 30901².

It is a happy number.

It is a balanced prime because it is at equal distance from previous prime (1909681759) and next prime (1909681843).

It can be written as a sum of positive squares in only one way, i.e., 954871801 + 954810000 = 30901^2 + 30900^2 .

It is a cyclic number.

It is not a de Polignac number, because 1909681801 - 2⁷ = 1909681673 is a prime.

It is not a weakly prime, because it can be changed into another prime (1909688801) 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, 954840900 + 954840901.

It is an arithmetic number, because the mean of its divisors is an integer number (954840901).

Almost surely, 2^1909681801 is an apocalyptic number.

1909681801 is the 30901-st centered square number.

It is an amenable number.

1909681801 is a deficient number, since it is larger than the sum of its proper divisors (1).

1909681801 is an equidigital number, since it uses as much as digits as its factorization.

1909681801 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 31104, while the sum is 43.

The square root of 1909681801 is about 43699.9061898307. The cubic root of 1909681801 is about 1240.6625407079.

The spelling of 1909681801 in words is "one billion, nine hundred nine million, six hundred eighty-one thousand, eight hundred one".