1684661 has 4 divisors (see below), whose sum is σ = 1837824. Its totient is φ = 1531500.

The previous prime is 1684609. The next prime is 1684667. The reversal of 1684661 is 1664861.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 1684661 - 2¹⁰ = 1683637 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1684667) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 76565 + ... + 76586.

It is an arithmetic number, because the mean of its divisors is an integer number (459456).

2^1684661 is an apocalyptic number.

1684661 is a gapful number since it is divisible by the number (11) formed by its first and last digit.

It is an amenable number.

1684661 is a deficient number, since it is larger than the sum of its proper divisors (153163).

1684661 is a wasteful number, since it uses less digits than its factorization.

1684661 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 153162.

The product of its digits is 6912, while the sum is 32.

The square root of 1684661 is about 1297.9449140853. The cubic root of 1684661 is about 118.9882765091.

The spelling of 1684661 in words is "one million, six hundred eighty-four thousand, six hundred sixty-one".