1001785866 has 16 divisors (see below), whose sum is σ = 2007561024. Its totient is φ = 333263744.

The previous prime is 1001785787. The next prime is 1001785867. The reversal of 1001785866 is 6685871001.

It is not an unprimeable number, because it can be changed into a prime (1001785867) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 162951 + ... + 168986.

It is an arithmetic number, because the mean of its divisors is an integer number (125472564).

Almost surely, 2^1001785866 is an apocalyptic number.

1001785866 is an abundant number, since it is smaller than the sum of its proper divisors (1005775158).

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

1001785866 is a wasteful number, since it uses less digits than its factorization.

1001785866 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 332445.

The product of its (nonzero) digits is 80640, while the sum is 42.

The square root of 1001785866 is about 31651.0010268238. The cubic root of 1001785866 is about 1000.5949346492.

The spelling of 1001785866 in words is "one billion, one million, seven hundred eighty-five thousand, eight hundred sixty-six".