9780891 has 4 divisors (see below), whose sum is σ = 13041192. Its totient is φ = 6520592.

The previous prime is 9780887. The next prime is 9780893. The reversal of 9780891 is 1980879.

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 9780891 - 2² = 9780887 is a prime.

It is not an unprimeable number, because it can be changed into a prime (9780893) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 1630146 + ... + 1630151.

It is an arithmetic number, because the mean of its divisors is an integer number (3260298).

Almost surely, 2^9780891 is an apocalyptic number.

9780891 is a deficient number, since it is larger than the sum of its proper divisors (3260301).

9780891 is a wasteful number, since it uses less digits than its factorization.

9780891 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3260300.

The product of its (nonzero) digits is 36288, while the sum is 42.

The square root of 9780891 is about 3127.4416061695. The cubic root of 9780891 is about 213.8583145168.

The spelling of 9780891 in words is "nine million, seven hundred eighty thousand, eight hundred ninety-one".