987055021 has 2 divisors, whose sum is σ = 987055022. Its totient is φ = 987055020.

The previous prime is 987055019. The next prime is 987055079. The reversal of 987055021 is 120550789.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 985080996 + 1974025 = 31386^2 + 1405^2 .

It is an emirp because it is prime and its reverse (120550789) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 987055021 - 2¹ = 987055019 is a prime.

It is a super-2 number, since 2×987055021² = 1948555228962620882, which contains 22 as substring.

Together with 987055019, it forms a pair of twin primes.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (987055621) 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, 493527510 + 493527511.

It is an arithmetic number, because the mean of its divisors is an integer number (493527511).

Almost surely, 2^987055021 is an apocalyptic number.

It is an amenable number.

987055021 is a deficient number, since it is larger than the sum of its proper divisors (1).

987055021 is an equidigital number, since it uses as much as digits as its factorization.

987055021 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 25200, while the sum is 37.

The square root of 987055021 is about 31417.4318014697. The cubic root of 987055021 is about 995.6662527661. Note that the first 3 decimals are identical.

The spelling of 987055021 in words is "nine hundred eighty-seven million, fifty-five thousand, twenty-one".