87989987 has 2 divisors, whose sum is σ = 87989988. Its totient is φ = 87989986.

The previous prime is 87989981. The next prime is 87990029. The reversal of 87989987 is 78998978.

It is a weak prime.

It is a cyclic number.

It is not a de Polignac number, because 87989987 - 2²² = 83795683 is a prime.

It is a Chen prime.

It is not a weakly prime, because it can be changed into another prime (87989981) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (17) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 43994993 + 43994994.

It is an arithmetic number, because the mean of its divisors is an integer number (43994994).

Almost surely, 2^87989987 is an apocalyptic number.

87989987 is a deficient number, since it is larger than the sum of its proper divisors (1).

87989987 is an equidigital number, since it uses as much as digits as its factorization.

87989987 is an odious number, because the sum of its binary digits is odd.

The product of its digits is 18289152, while the sum is 65.

The square root of 87989987 is about 9380.2978097713. The cubic root of 87989987 is about 444.7791472371.

The spelling of 87989987 in words is "eighty-seven million, nine hundred eighty-nine thousand, nine hundred eighty-seven".