87717840 has 120 divisors (see below), whose sum is σ = 316363680. Its totient is φ = 20047104.

The previous prime is 87717829. The next prime is 87717857. The reversal of 87717840 is 4871778.

It is a tau number, because it is divible by the number of its divisors (120).

It is a hoax number, since the sum of its digits (42) coincides with the sum of the digits of its distinct prime factors.

It is a Harshad number since it is a multiple of its sum of digits (42).

It is a junction number, because it is equal to n+sod(n) for n = 87717792 and 87717801.

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 23 ways as a sum of consecutive naturals, for example, 8031 + ... + 15489.

It is an arithmetic number, because the mean of its divisors is an integer number (2636364).

Almost surely, 2^87717840 is an apocalyptic number.

87717840 is a gapful number since it is divisible by the number (80) formed by its first and last digit.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 87717840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (158181840).

87717840 is an abundant number, since it is smaller than the sum of its proper divisors (228645840).

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

87717840 is a wasteful number, since it uses less digits than its factorization.

87717840 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7489 (or 7476 counting only the distinct ones).

The product of its (nonzero) digits is 87808, while the sum is 42.

The square root of 87717840 is about 9365.7802664807. The cubic root of 87717840 is about 444.3201165203.

The spelling of 87717840 in words is "eighty-seven million, seven hundred seventeen thousand, eight hundred forty".