987478109 has 2 divisors, whose sum is σ = 987478110. Its totient is φ = 987478108.

The previous prime is 987478091. The next prime is 987478147. The reversal of 987478109 is 901874789.

Together with previous prime (987478091) it forms an Ormiston pair, because they use the same digits, order apart.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 840826009 + 146652100 = 28997^2 + 12110^2 .

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-987478109 is a prime.

It is a super-2 number, since 2×987478109² = 1950226031508431762, which contains 22 as substring.

It is a Chen prime.

It is an alternating number because its digits alternate between odd and even.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (987478169) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (19) of ones.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 493739054 + 493739055.

It is an arithmetic number, because the mean of its divisors is an integer number (493739055).

Almost surely, 2^987478109 is an apocalyptic number.

It is an amenable number.

987478109 is a deficient number, since it is larger than the sum of its proper divisors (1).

987478109 is an equidigital number, since it uses as much as digits as its factorization.

987478109 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 1016064, while the sum is 53.

The square root of 987478109 is about 31424.1644121208. The cubic root of 987478109 is about 995.8084921417.

The spelling of 987478109 in words is "nine hundred eighty-seven million, four hundred seventy-eight thousand, one hundred nine".