87665820 has 96 divisors (see below), whose sum is σ = 274095360. Its totient is φ = 20751360.

The previous prime is 87665819. The next prime is 87665843. The reversal of 87665820 is 2856678.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 31 ways as a sum of consecutive naturals, for example, 26836 + ... + 29924.

It is an arithmetic number, because the mean of its divisors is an integer number (2855160).

Almost surely, 2^87665820 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 87665820, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (137047680).

87665820 is an abundant number, since it is smaller than the sum of its proper divisors (186429540).

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

87665820 is a wasteful number, since it uses less digits than its factorization.

87665820 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 3155 (or 3153 counting only the distinct ones).

The product of its (nonzero) digits is 161280, while the sum is 42.

The square root of 87665820 is about 9363.0027234857. The cubic root of 87665820 is about 444.2322662684.

It can be divided in two parts, 876658 and 20, that added together give a palindrome (876678).

The spelling of 87665820 in words is "eighty-seven million, six hundred sixty-five thousand, eight hundred twenty".