87665770 has 16 divisors (see below), whose sum is σ = 167080968. Its totient is φ = 33003520.

The previous prime is 87665741. The next prime is 87665779. The reversal of 87665770 is 7756678.

It is a Cunningham number, because it is equal to 9363²+1.

It can be written as a sum of positive squares in 4 ways, for example, as 87665769 + 1 = 9363^2 + 1^2 .

It is a self number, because there is not a number n which added to its sum of digits gives 87665770.

It is not an unprimeable number, because it can be changed into a prime (87665779) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 257671 + ... + 258010.

Almost surely, 2^87665770 is an apocalyptic number.

87665770 is a deficient number, since it is larger than the sum of its proper divisors (79415198).

87665770 is a wasteful number, since it uses less digits than its factorization.

87665770 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 515705.

The product of its (nonzero) digits is 493920, while the sum is 46.

The square root of 87665770 is about 9363.0000534017. Note that the first 4 decimals coincide. The cubic root of 87665770 is about 444.2321818127.

The spelling of 87665770 in words is "eighty-seven million, six hundred sixty-five thousand, seven hundred seventy".