1666666666650 has 48 divisors (see below), whose sum is σ = 4133532312000. Its totient is φ = 444423048960.

The previous prime is 1666666666573. The next prime is 1666666666657. The reversal of 1666666666650 is 566666666661.

It is a happy number.

It is a Curzon number.

It is not an unprimeable number, because it can be changed into a prime (1666666666657) by changing a digit.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 2990731 + ... + 3503969.

It is an arithmetic number, because the mean of its divisors is an integer number (86115256500).

Almost surely, 2^{1666666666650} is an apocalyptic number.

1666666666650 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

1666666666650 is an abundant number, since it is smaller than the sum of its proper divisors (2466865645350).

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

1666666666650 is a wasteful number, since it uses less digits than its factorization.

1666666666650 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 534903 (or 534898 counting only the distinct ones).

The product of its (nonzero) digits is 302330880, while the sum is 66.

It can be divided in two parts, 16 and 66666666650, that added together give a palindrome (66666666666).

The spelling of 1666666666650 in words is "one trillion, six hundred sixty-six billion, six hundred sixty-six million, six hundred sixty-six thousand, six hundred fifty".