1660091 has 4 divisors (see below), whose sum is σ = 1662792. Its totient is φ = 1657392.

The previous prime is 1660073. The next prime is 1660097. The reversal of 1660091 is 1900661.

It is a semiprime because it is the product of two primes.

It is a cyclic number.

It is not a de Polignac number, because 1660091 - 2¹⁰ = 1659067 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (1660097) 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, 71 + ... + 1823.

It is an arithmetic number, because the mean of its divisors is an integer number (415698).

2^1660091 is an apocalyptic number.

1660091 is a deficient number, since it is larger than the sum of its proper divisors (2701).

1660091 is an equidigital number, since it uses as much as digits as its factorization.

1660091 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2700.

The product of its (nonzero) digits is 324, while the sum is 23.

The square root of 1660091 is about 1288.4451870375. The cubic root of 1660091 is about 118.4069783369.

The spelling of 1660091 in words is "one million, six hundred sixty thousand, ninety-one".