8981991 has 12 divisors (see below), whose sum is σ = 13019760. Its totient is φ = 5966880.

The previous prime is 8981989. The next prime is 8982007. The reversal of 8981991 is 1991898.

8981991 is digitally balanced in base 2 and base 4, because in such bases it contains all the possibile digits an equal number of times.

It is not a de Polignac number, because 8981991 - 2¹ = 8981989 is a prime.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (8981941) by changing a digit.

It is a polite number, since it can be written in 11 ways as a sum of consecutive naturals, for example, 1195 + ... + 4403.

It is an arithmetic number, because the mean of its divisors is an integer number (1084980).

Almost surely, 2^8981991 is an apocalyptic number.

8981991 is a deficient number, since it is larger than the sum of its proper divisors (4037769).

8981991 is a wasteful number, since it uses less digits than its factorization.

8981991 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3526 (or 3523 counting only the distinct ones).

The product of its digits is 46656, while the sum is 45.

The square root of 8981991 is about 2996.9969969955. The cubic root of 8981991 is about 207.8695480705.

The spelling of 8981991 in words is "eight million, nine hundred eighty-one thousand, nine hundred ninety-one".