1866808117 has 4 divisors (see below), whose sum is σ = 1877122156. Its totient is φ = 1856494080.

The previous prime is 1866808109. The next prime is 1866808123. The reversal of 1866808117 is 7118086681.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 7118086681 = 9871 ⋅721111.

It can be written as a sum of positive squares in 2 ways, for example, as 180391761 + 1686416356 = 13431^2 + 41066^2 .

It is a cyclic number.

It is not a de Polignac number, because 1866808117 - 2³ = 1866808109 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 (1866808147) 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, 5156748 + ... + 5157109.

It is an arithmetic number, because the mean of its divisors is an integer number (469280539).

Almost surely, 2^1866808117 is an apocalyptic number.

It is an amenable number.

1866808117 is a deficient number, since it is larger than the sum of its proper divisors (10314039).

1866808117 is a wasteful number, since it uses less digits than its factorization.

1866808117 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 10314038.

The product of its (nonzero) digits is 129024, while the sum is 46.

The square root of 1866808117 is about 43206.5749278973. The cubic root of 1866808117 is about 1231.3076003115.

The spelling of 1866808117 in words is "one billion, eight hundred sixty-six million, eight hundred eight thousand, one hundred seventeen".