1667661 has 8 divisors (see below), whose sum is σ = 2320320. Its totient is φ = 1063392.

The previous prime is 1667651. The next prime is 1667663.

1667661 is nontrivially palindromic in base 10.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 1667661 - 2⁵ = 1667629 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1667663) 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 7 ways as a sum of consecutive naturals, for example, 12016 + ... + 12153.

It is an arithmetic number, because the mean of its divisors is an integer number (290040).

2^1667661 is an apocalyptic number.

It is an amenable number.

1667661 is a deficient number, since it is larger than the sum of its proper divisors (652659).

1667661 is a wasteful number, since it uses less digits than its factorization.

1667661 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 24195.

The product of its digits is 9072, while the sum is 33.

The square root of 1667661 is about 1291.3794949588. The cubic root of 1667661 is about 118.5866837128.

The spelling of 1667661 in words is "one million, six hundred sixty-seven thousand, six hundred sixty-one".