1866666361 has 16 divisors (see below), whose sum is σ = 2228428800. Its totient is φ = 1528824528.

The previous prime is 1866666337. The next prime is 1866666377. The reversal of 1866666361 is 1636666681.

It is a happy number.

It is not a de Polignac number, because 1866666361 - 2⁷ = 1866666233 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1866666661) 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, 161700 + ... + 172858.

It is an arithmetic number, because the mean of its divisors is an integer number (139276800).

Almost surely, 2^1866666361 is an apocalyptic number.

It is an amenable number.

1866666361 is a deficient number, since it is larger than the sum of its proper divisors (361762439).

1866666361 is a wasteful number, since it uses less digits than its factorization.

1866666361 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12228.

The product of its digits is 1119744, while the sum is 49.

The square root of 1866666361 is about 43204.9344519813. The cubic root of 1866666361 is about 1231.2764330914.

The spelling of 1866666361 in words is "one billion, eight hundred sixty-six million, six hundred sixty-six thousand, three hundred sixty-one".