987206557 has 4 divisors (see below), whose sum is σ = 988148700. Its totient is φ = 986264416.

The previous prime is 987206551. The next prime is 987206573. The reversal of 987206557 is 755602789.

It is a semiprime because it is the product of two primes, and also an emirpimes, since its reverse is a distinct semiprime: 755602789 = 37 ⋅20421697.

It can be written as a sum of positive squares in 2 ways, for example, as 723663801 + 263542756 = 26901^2 + 16234^2 .

It is a cyclic number.

It is not a de Polignac number, because 987206557 - 2¹⁹ = 986682269 is a prime.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 987206557.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (987206551) 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 in 3 ways as a sum of consecutive naturals, for example, 469498 + ... + 471595.

It is an arithmetic number, because the mean of its divisors is an integer number (247037175).

Almost surely, 2^987206557 is an apocalyptic number.

It is an amenable number.

987206557 is a deficient number, since it is larger than the sum of its proper divisors (942143).

987206557 is a wasteful number, since it uses less digits than its factorization.

987206557 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 942142.

The product of its (nonzero) digits is 1058400, while the sum is 49.

The square root of 987206557 is about 31419.8433637089. The cubic root of 987206557 is about 995.7172028340.

The spelling of 987206557 in words is "nine hundred eighty-seven million, two hundred six thousand, five hundred fifty-seven".