1670391 has 6 divisors (see below), whose sum is σ = 2412800. Its totient is φ = 1113588.

The previous prime is 1670359. The next prime is 1670399. The reversal of 1670391 is 1930761.

It is not a de Polignac number, because 1670391 - 2⁵ = 1670359 is a prime.

It is a Duffinian number.

1670391 is a lucky number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (1670399) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 92791 + ... + 92808.

2^1670391 is an apocalyptic number.

1670391 is a deficient number, since it is larger than the sum of its proper divisors (742409).

1670391 is a wasteful number, since it uses less digits than its factorization.

1670391 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 185605 (or 185602 counting only the distinct ones).

The product of its (nonzero) digits is 1134, while the sum is 27.

The square root of 1670391 is about 1292.4360719200. The cubic root of 1670391 is about 118.6513581579.

It can be divided in two parts, 16 and 70391, that added together give a palindrome (70407).

The spelling of 1670391 in words is "one million, six hundred seventy thousand, three hundred ninety-one".