1187645866 has 16 divisors (see below), whose sum is σ = 1943958528. Its totient is φ = 539689600.

The previous prime is 1187645861. The next prime is 1187645909. The reversal of 1187645866 is 6685467811.

It is not an unprimeable number, because it can be changed into a prime (1187645861) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 130071 + ... + 138901.

It is an arithmetic number, because the mean of its divisors is an integer number (121497408).

Almost surely, 2^1187645866 is an apocalyptic number.

1187645866 is a deficient number, since it is larger than the sum of its proper divisors (756312662).

1187645866 is a wasteful number, since it uses less digits than its factorization.

1187645866 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 14957.

The product of its digits is 1935360, while the sum is 52.

The square root of 1187645866 is about 34462.2382616103. The cubic root of 1187645866 is about 1058.9992530705. Note that the first 3 decimals are identical.

The spelling of 1187645866 in words is "one billion, one hundred eighty-seven million, six hundred forty-five thousand, eight hundred sixty-six".