891868521 has 8 divisors (see below), whose sum is σ = 1205448160. Its totient is φ = 586433952.

The previous prime is 891868517. The next prime is 891868529. The reversal of 891868521 is 125868198.

891868521 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 891868521 - 2² = 891868517 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (891868529) 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, 2036011 + ... + 2036448.

It is an arithmetic number, because the mean of its divisors is an integer number (150681020).

Almost surely, 2^891868521 is an apocalyptic number.

It is an amenable number.

891868521 is a deficient number, since it is larger than the sum of its proper divisors (313579639).

891868521 is a wasteful number, since it uses less digits than its factorization.

891868521 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 4072535.

The product of its digits is 276480, while the sum is 48.

The square root of 891868521 is about 29864.1678437555. The cubic root of 891868521 is about 962.5728586214.

The spelling of 891868521 in words is "eight hundred ninety-one million, eight hundred sixty-eight thousand, five hundred twenty-one".