87640 has 32 divisors (see below), whose sum is σ = 226080. Its totient is φ = 29952.

The previous prime is 87631. The next prime is 87641. The reversal of 87640 is 4678.

It is a Smith number, since the sum of its digits (25) coincides with the sum of the digits of its prime factors.

It is a nialpdrome in base 10.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (87641) by changing a digit.

87640 is an untouchable number, because it is not equal to the sum of proper divisors of any number.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 124 + ... + 436.

It is an arithmetic number, because the mean of its divisors is an integer number (7065).

2⁸⁷⁶⁴⁰ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 87640, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (113040).

87640 is an abundant number, since it is smaller than the sum of its proper divisors (138440).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

87640 is a wasteful number, since it uses less digits than its factorization.

87640 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 331 (or 327 counting only the distinct ones).

The product of its (nonzero) digits is 1344, while the sum is 25.

The square root of 87640 is about 296.0405377647. The cubic root of 87640 is about 44.4188649104.

It can be divided in two parts, 87 and 640, that added together give a palindrome (727).

The spelling of 87640 in words is "eighty-seven thousand, six hundred forty".