987553 has 4 divisors (see below), whose sum is σ = 1128640. Its totient is φ = 846468.

The previous prime is 987541. The next prime is 987559. The reversal of 987553 is 355789.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is not a de Polignac number, because 987553 - 2¹³ = 979361 is a prime.

It is a Duffinian number.

It is a nialpdrome in base 10.

It is not an unprimeable number, because it can be changed into a prime (987559) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 70533 + ... + 70546.

It is an arithmetic number, because the mean of its divisors is an integer number (282160).

2⁹⁸⁷⁵⁵³ is an apocalyptic number.

It is an amenable number.

987553 is a deficient number, since it is larger than the sum of its proper divisors (141087).

987553 is a wasteful number, since it uses less digits than its factorization.

987553 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 141086.

The product of its digits is 37800, while the sum is 37.

The square root of 987553 is about 993.7570125539. The cubic root of 987553 is about 99.5833665766.

It can be divided in two parts, 987 and 553, that added together give a triangular number (1540 = T₅₅).

The spelling of 987553 in words is "nine hundred eighty-seven thousand, five hundred fifty-three".