1909860061 has 4 divisors (see below), whose sum is σ = 1910489500. Its totient is φ = 1909230624.

The previous prime is 1909860049. The next prime is 1909860083. The reversal of 1909860061 is 1600689091.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 1600689091 = 3389 ⋅472319.

It can be written as a sum of positive squares in 2 ways, for example, as 829094436 + 1080765625 = 28794^2 + 32875^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-1909860061 is a prime.

It is a Duffinian number.

It is a junction number, because it is equal to n+sod(n) for n = 1909859996 and 1909860023.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1909861061) 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, 310146 + ... + 316243.

It is an arithmetic number, because the mean of its divisors is an integer number (477622375).

Almost surely, 2^1909860061 is an apocalyptic number.

It is an amenable number.

1909860061 is a deficient number, since it is larger than the sum of its proper divisors (629439).

1909860061 is an equidigital number, since it uses as much as digits as its factorization.

1909860061 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 629438.

The product of its (nonzero) digits is 23328, while the sum is 40.

The square root of 1909860061 is about 43701.9457347153. The cubic root of 1909860061 is about 1240.7011428847.

The spelling of 1909860061 in words is "one billion, nine hundred nine million, eight hundred sixty thousand, sixty-one".