1851851851866 has 12 divisors (see below), whose sum is σ = 4012345679082. Its totient is φ = 617283950616.

The previous prime is 1851851851859. The next prime is 1851851851867. The reversal of 1851851851866 is 6681581581581.

1851851851866 is a `hidden beast` number, since 1 + 8 + 5 + 1 + 8 + 51 + 8 + 518 + 66 = 666.

It can be written as a sum of positive squares in only one way, i.e., 1851719486841 + 132365025 = 1360779^2 + 11505^2 .

It is not an unprimeable number, because it can be changed into a prime (1851851851867) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 51440329201 + ... + 51440329236.

Almost surely, 2^{1851851851866} is an apocalyptic number.

1851851851866 is an abundant number, since it is smaller than the sum of its proper divisors (2160493827216).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

1851851851866 is a wasteful number, since it uses less digits than its factorization.

1851851851866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 102880658445 (or 102880658442 counting only the distinct ones).

The product of its digits is 18432000, while the sum is 63.

The spelling of 1851851851866 in words is "one trillion, eight hundred fifty-one billion, eight hundred fifty-one million, eight hundred fifty-one thousand, eight hundred sixty-six".