1667861 has 12 divisors (see below), whose sum is σ = 1844640. Its totient is φ = 1506960.

The previous prime is 1667851. The next prime is 1667863. The reversal of 1667861 is 1687661.

It is not a de Polignac number, because 1667861 - 2¹⁴ = 1651477 is a prime.

It is an Ulam number.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1667863) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 11930 + ... + 12068.

It is an arithmetic number, because the mean of its divisors is an integer number (153720).

2^1667861 is an apocalyptic number.

It is an amenable number.

1667861 is a deficient number, since it is larger than the sum of its proper divisors (176779).

1667861 is a wasteful number, since it uses less digits than its factorization.

1667861 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 236 (or 223 counting only the distinct ones).

The product of its digits is 12096, while the sum is 35.

The square root of 1667861 is about 1291.4569292082. The cubic root of 1667861 is about 118.5914241624.

The spelling of 1667861 in words is "one million, six hundred sixty-seven thousand, eight hundred sixty-one".