1591966 has 4 divisors (see below), whose sum is σ = 2387952. Its totient is φ = 795982.

The previous prime is 1591949. The next prime is 1591969. The reversal of 1591966 is 6691951.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 6691951 = 7 ⋅955993.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1591969) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 397990 + ... + 397993.

It is an arithmetic number, because the mean of its divisors is an integer number (596988).

2^1591966 is an apocalyptic number.

1591966 is a deficient number, since it is larger than the sum of its proper divisors (795986).

1591966 is an equidigital number, since it uses as much as digits as its factorization.

1591966 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 795985.

The product of its digits is 14580, while the sum is 37.

The square root of 1591966 is about 1261.7313501693. The cubic root of 1591966 is about 116.7646179655.

The spelling of 1591966 in words is "one million, five hundred ninety-one thousand, nine hundred sixty-six".