1000391 has 8 divisors (see below), whose sum is σ = 1149984. Its totient is φ = 852480.

The previous prime is 1000381. The next prime is 1000393. The reversal of 1000391 is 1930001.

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

It is a cyclic number.

It is not a de Polignac number, because 1000391 - 2¹⁴ = 984007 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 (1000393) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 1391 + ... + 1983.

It is an arithmetic number, because the mean of its divisors is an integer number (143748).

2^1000391 is an apocalyptic number.

1000391 is a deficient number, since it is larger than the sum of its proper divisors (149593).

1000391 is an equidigital number, since it uses as much as digits as its factorization.

1000391 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 841.

The product of its (nonzero) digits is 27, while the sum is 14.

The square root of 1000391 is about 1000.1954808936. The cubic root of 1000391 is about 100.0130316350.

Adding to 1000391 its sum of digits (14), we get a triangular number (1000405 = T₁₄₁₄).

Adding to 1000391 its reverse (1930001), we get a palindrome (2930392).

The spelling of 1000391 in words is "one million, three hundred ninety-one", and thus it is an aban number.