1909409801 has 16 divisors (see below), whose sum is σ = 2069277840. Its totient is φ = 1751439360.

The previous prime is 1909409783. The next prime is 1909409809. The reversal of 1909409801 is 1089049091.

It can be written as a sum of positive squares in 8 ways, for example, as 145829776 + 1763580025 = 12076^2 + 41995^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1909409801 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1909409809) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 2166881 + ... + 2167761.

It is an arithmetic number, because the mean of its divisors is an integer number (129329865).

Almost surely, 2^1909409801 is an apocalyptic number.

It is an amenable number.

1909409801 is a deficient number, since it is larger than the sum of its proper divisors (159868039).

1909409801 is a wasteful number, since it uses less digits than its factorization.

1909409801 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1756.

The product of its (nonzero) digits is 23328, while the sum is 41.

The square root of 1909409801 is about 43696.7939441786. The cubic root of 1909409801 is about 1240.6036345184.

The spelling of 1909409801 in words is "one billion, nine hundred nine million, four hundred nine thousand, eight hundred one".