891651 has 8 divisors (see below), whose sum is σ = 1251520. Its totient is φ = 563112.

The previous prime is 891647. The next prime is 891659. The reversal of 891651 is 156198.

It is a happy number.

891651 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

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

It is not a de Polignac number, because 891651 - 2² = 891647 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (891659) 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, 7765 + ... + 7878.

It is an arithmetic number, because the mean of its divisors is an integer number (156440).

2⁸⁹¹⁶⁵¹ is an apocalyptic number.

891651 is a deficient number, since it is larger than the sum of its proper divisors (359869).

891651 is a wasteful number, since it uses less digits than its factorization.

891651 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 15665.

The product of its digits is 2160, while the sum is 30.

The square root of 891651 is about 944.2727360249. The cubic root of 891651 is about 96.2494597147.

The spelling of 891651 in words is "eight hundred ninety-one thousand, six hundred fifty-one".