87989761 has 4 divisors (see below), whose sum is σ = 88978500. Its totient is φ = 87001024.

The previous prime is 87989723. The next prime is 87989809. The reversal of 87989761 is 16798978.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 20421361 + 67568400 = 4519^2 + 8220^2 .

It is a cyclic number.

It is not a de Polignac number, because 87989761 - 2¹⁵ = 87956993 is a prime.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (87959761) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (13) of ones.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 494236 + ... + 494413.

It is an arithmetic number, because the mean of its divisors is an integer number (22244625).

Almost surely, 2^87989761 is an apocalyptic number.

It is an amenable number.

87989761 is a deficient number, since it is larger than the sum of its proper divisors (988739).

87989761 is an equidigital number, since it uses as much as digits as its factorization.

87989761 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 988738.

The product of its digits is 1524096, while the sum is 55.

The square root of 87989761 is about 9380.2857632377. The cubic root of 87989761 is about 444.7787664356.

The spelling of 87989761 in words is "eighty-seven million, nine hundred eighty-nine thousand, seven hundred sixty-one".