987090691 has 2 divisors, whose sum is σ = 987090692. Its totient is φ = 987090690.

The previous prime is 987090677. The next prime is 987090733. The reversal of 987090691 is 196090789.

It is a weak prime.

It is an emirp because it is prime and its reverse (196090789) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 987090691 - 2¹⁹ = 986566403 is a prime.

It is not a weakly prime, because it can be changed into another prime (987090631) 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, 493545345 + 493545346.

It is an arithmetic number, because the mean of its divisors is an integer number (493545346).

Almost surely, 2^987090691 is an apocalyptic number.

987090691 is a deficient number, since it is larger than the sum of its proper divisors (1).

987090691 is an equidigital number, since it uses as much as digits as its factorization.

987090691 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 244944, while the sum is 49.

The square root of 987090691 is about 31417.9994748233. Note that the first 3 decimals coincide. The cubic root of 987090691 is about 995.6782463520.

The spelling of 987090691 in words is "nine hundred eighty-seven million, ninety thousand, six hundred ninety-one".