9071981 has 4 divisors (see below), whose sum is σ = 9220764. Its totient is φ = 8923200.

The previous prime is 9071977. The next prime is 9071989. The reversal of 9071981 is 1891709.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 422500 + 8649481 = 650^2 + 2941^2 .

It is a cyclic number.

It is not a de Polignac number, because 9071981 - 2² = 9071977 is a prime.

It is a super-2 number, since 2×9071981² = 164601678528722, which contains 22 as substring.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (9071989) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 74300 + ... + 74421.

It is an arithmetic number, because the mean of its divisors is an integer number (2305191).

Almost surely, 2^9071981 is an apocalyptic number.

It is an amenable number.

9071981 is a deficient number, since it is larger than the sum of its proper divisors (148783).

9071981 is a wasteful number, since it uses less digits than its factorization.

9071981 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 148782.

The product of its (nonzero) digits is 4536, while the sum is 35.

The square root of 9071981 is about 3011.9729414455. The cubic root of 9071981 is about 208.5614530923.

The spelling of 9071981 in words is "nine million, seventy-one thousand, nine hundred eighty-one".