7181989 has 4 divisors (see below), whose sum is σ = 7349056. Its totient is φ = 7014924.

The previous prime is 7181983. The next prime is 7182001. The reversal of 7181989 is 9891817.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is not a de Polignac number, because 7181989 - 2⁷ = 7181861 is a prime.

It is a super-2 number, since 2×7181989² = 103161931992242, which contains 22 as substring.

It is a Harshad number since it is a multiple of its sum of digits (43), and also a Moran number because the ratio is a prime number: 167023 = 7181989 / (7 + 1 + 8 + 1 + 9 + 8 + 9).

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7181983) 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, 83469 + ... + 83554.

It is an arithmetic number, because the mean of its divisors is an integer number (1837264).

Almost surely, 2^7181989 is an apocalyptic number.

It is an amenable number.

7181989 is a deficient number, since it is larger than the sum of its proper divisors (167067).

7181989 is a wasteful number, since it uses less digits than its factorization.

7181989 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 167066.

The product of its digits is 36288, while the sum is 43.

The square root of 7181989 is about 2679.9233197985. The cubic root of 7181989 is about 192.9367292402.

The spelling of 7181989 in words is "seven million, one hundred eighty-one thousand, nine hundred eighty-nine".