1666667685 has 16 divisors (see below), whose sum is σ = 2685856320. Its totient is φ = 882493440.

The previous prime is 1666667683. The next prime is 1666667687. The reversal of 1666667685 is 5867666661.

It is an interprime number because it is at equal distance from previous prime (1666667683) and next prime (1666667687).

It is not a de Polignac number, because 1666667685 - 2¹ = 1666667683 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1666667683) 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, 397596 + ... + 401765.

It is an arithmetic number, because the mean of its divisors is an integer number (167866020).

Almost surely, 2^1666667685 is an apocalyptic number.

1666667685 is a gapful number since it is divisible by the number (15) formed by its first and last digit.

It is an amenable number.

1666667685 is a deficient number, since it is larger than the sum of its proper divisors (1019188635).

1666667685 is a wasteful number, since it uses less digits than its factorization.

1666667685 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 799508.

The product of its digits is 13063680, while the sum is 57.

The square root of 1666667685 is about 40824.8415183697. The cubic root of 1666667685 is about 1185.6313429702.

The spelling of 1666667685 in words is "one billion, six hundred sixty-six million, six hundred sixty-seven thousand, six hundred eighty-five".