617891 has 4 divisors (see below), whose sum is σ = 619752. Its totient is φ = 616032.

The previous prime is 617887. The next prime is 617917. The reversal of 617891 is 198716.

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 617891 - 2² = 617887 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (617801) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 281 + ... + 1146.

It is an arithmetic number, because the mean of its divisors is an integer number (154938).

2⁶¹⁷⁸⁹¹ is an apocalyptic number.

617891 is a deficient number, since it is larger than the sum of its proper divisors (1861).

617891 is a wasteful number, since it uses less digits than its factorization.

617891 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 1860.

The product of its digits is 3024, while the sum is 32.

The square root of 617891 is about 786.0604302469. The cubic root of 617891 is about 85.1733946037.

The spelling of 617891 in words is "six hundred seventeen thousand, eight hundred ninety-one".