7989987 has 8 divisors (see below), whose sum is σ = 10763536. Its totient is φ = 5271552.

The previous prime is 7989973. The next prime is 7990001. The reversal of 7989987 is 7899897.

It is a happy number.

It is an interprime number because it is at equal distance from previous prime (7989973) and next prime (7990001).

It is a sphenic number, since it is the product of 3 distinct primes.

It is a de Polignac number, because none of the positive numbers 2^k-7989987 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (7989907) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 13438 + ... + 14019.

It is an arithmetic number, because the mean of its divisors is an integer number (1345442).

Almost surely, 2^7989987 is an apocalyptic number.

7989987 is a deficient number, since it is larger than the sum of its proper divisors (2773549).

7989987 is a wasteful number, since it uses less digits than its factorization.

7989987 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27557.

The product of its digits is 2286144, while the sum is 57.

The square root of 7989987 is about 2826.6565054849. The cubic root of 7989987 is about 199.9165234965.

The spelling of 7989987 in words is "seven million, nine hundred eighty-nine thousand, nine hundred eighty-seven".