987665261 has 4 divisors (see below), whose sum is σ = 1077453024. Its totient is φ = 897877500.

The previous prime is 987665243. The next prime is 987665281. The reversal of 987665261 is 162566789.

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 a cyclic number.

It is a de Polignac number, because none of the positive numbers 2^k-987665261 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (987665281) 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, 44893865 + ... + 44893886.

It is an arithmetic number, because the mean of its divisors is an integer number (269363256).

Almost surely, 2^987665261 is an apocalyptic number.

It is an amenable number.

987665261 is a deficient number, since it is larger than the sum of its proper divisors (89787763).

987665261 is a wasteful number, since it uses less digits than its factorization.

987665261 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 89787762.

The product of its digits is 1088640, while the sum is 50.

The square root of 987665261 is about 31427.1421067841. The cubic root of 987665261 is about 995.8713984403.

The spelling of 987665261 in words is "nine hundred eighty-seven million, six hundred sixty-five thousand, two hundred sixty-one".