87665769 has 9 divisors (see below), whose sum is σ = 126668919. Its totient is φ = 58425120.

The previous prime is 87665741. The next prime is 87665779. The reversal of 87665769 is 96756678.

It is a happy number.

The square root of 87665769 is 9363.

It is a perfect power (a square), and thus also a powerful number.

87665769 is a `hidden beast` number, since 8 + 7 + 66 + 576 + 9 = 666.

It can be written as a sum of positive squares in only one way, i.e., 56169 + 87609600 = 237^2 + 9360^2 .

It is a tau number, because it is divible by the number of its divisors (9).

It is a de Polignac number, because none of the positive numbers 2^k-87665769 is a prime.

It is a super-2 number, since 2×87665769² = 15370574108722722, which contains 22 as substring.

It is not an unprimeable number, because it can be changed into a prime (87665729) by changing a digit.

It is a polite number, since it can be written in 8 ways as a sum of consecutive naturals, for example, 26529 + ... + 29649.

Almost surely, 2^87665769 is an apocalyptic number.

87665769 is the 9363-rd square number.

87665769 is the 4682-nd centered octagonal number.

It is an amenable number.

87665769 is a deficient number, since it is larger than the sum of its proper divisors (39003150).

87665769 is an frugal number, since it uses more digits than its factorization.

87665769 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 6248 (or 3124 counting only the distinct ones).

The product of its digits is 3810240, while the sum is 54.

The cubic root of 87665769 is about 444.2321801236.

Subtracting 87665769 from its reverse (96756678), we obtain a palindrome (9090909).

It can be divided in two parts, 8766 and 5769, that added together give a triangular number (14535 = T₁₇₀).

The spelling of 87665769 in words is "eighty-seven million, six hundred sixty-five thousand, seven hundred sixty-nine".