1306855861 has 4 divisors (see below), whose sum is σ = 1307515552. Its totient is φ = 1306196172.

The previous prime is 1306855859. The next prime is 1306855931. The reversal of 1306855861 is 1685586031.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1306855861 - 2¹ = 1306855859 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 (1306855811) 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, 326865 + ... + 330838.

It is an arithmetic number, because the mean of its divisors is an integer number (326878888).

Almost surely, 2^1306855861 is an apocalyptic number.

It is an amenable number.

1306855861 is a deficient number, since it is larger than the sum of its proper divisors (659691).

1306855861 is an equidigital number, since it uses as much as digits as its factorization.

1306855861 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 659690.

The product of its (nonzero) digits is 172800, while the sum is 43.

The square root of 1306855861 is about 36150.4614216748. The cubic root of 1306855861 is about 1093.3080940432.

The spelling of 1306855861 in words is "one billion, three hundred six million, eight hundred fifty-five thousand, eight hundred sixty-one".