816491 has 8 divisors (see below), whose sum is σ = 886704. Its totient is φ = 747360.

The previous prime is 816469. The next prime is 816499. The reversal of 816491 is 194618.

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 816491 - 2⁶ = 816427 is a prime.

It is not an unprimeable number, because it can be changed into a prime (816499) 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, 2180 + ... + 2526.

It is an arithmetic number, because the mean of its divisors is an integer number (110838).

2⁸¹⁶⁴⁹¹ is an apocalyptic number.

816491 is a deficient number, since it is larger than the sum of its proper divisors (70213).

816491 is a wasteful number, since it uses less digits than its factorization.

816491 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 541.

The product of its digits is 1728, while the sum is 29.

The square root of 816491 is about 903.5989154487. The cubic root of 816491 is about 93.4653135657.

The spelling of 816491 in words is "eight hundred sixteen thousand, four hundred ninety-one".