1909774085 has 4 divisors (see below), whose sum is σ = 2291728908. Its totient is φ = 1527819264.

The previous prime is 1909774081. The next prime is 1909774103. The reversal of 1909774085 is 5804779091.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 5804779091 = 19 ⋅305514689.

It can be written as a sum of positive squares in 2 ways, for example, as 1135487809 + 774286276 = 33697^2 + 27826^2 .

It is a cyclic number.

It is not a de Polignac number, because 1909774085 - 2² = 1909774081 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1909774081) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 190977404 + ... + 190977413.

It is an arithmetic number, because the mean of its divisors is an integer number (572932227).

Almost surely, 2^1909774085 is an apocalyptic number.

It is an amenable number.

1909774085 is a deficient number, since it is larger than the sum of its proper divisors (381954823).

1909774085 is an equidigital number, since it uses as much as digits as its factorization.

1909774085 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 381954822.

The product of its (nonzero) digits is 635040, while the sum is 50.

The square root of 1909774085 is about 43700.9620603483. The cubic root of 1909774085 is about 1240.6825250944.

The spelling of 1909774085 in words is "one billion, nine hundred nine million, seven hundred seventy-four thousand, eighty-five".