891640320 has 80 divisors (see below), whose sum is σ = 2850487200. Its totient is φ = 237768704.

The previous prime is 891640291. The next prime is 891640331. The reversal of 891640320 is 23046198.

It is a tau number, because it is divible by the number of its divisors (80).

It is an unprimeable number.

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 7 ways as a sum of consecutive naturals, for example, 50370 + ... + 65729.

It is an arithmetic number, because the mean of its divisors is an integer number (35631090).

Almost surely, 2^891640320 is an apocalyptic number.

891640320 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

891640320 is an abundant number, since it is smaller than the sum of its proper divisors (1958846880).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

891640320 is a wasteful number, since it uses less digits than its factorization.

891640320 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 116125 (or 116109 counting only the distinct ones).

The product of its (nonzero) digits is 10368, while the sum is 33.

The square root of 891640320 is about 29860.3469504291. The cubic root of 891640320 is about 962.4907542824.

The spelling of 891640320 in words is "eight hundred ninety-one million, six hundred forty thousand, three hundred twenty".