87747840 has 144 divisors (see below), whose sum is σ = 311505600. Its totient is φ = 23390208.

The previous prime is 87747839. The next prime is 87747853. The reversal of 87747840 is 4874778.

It is a tau number, because it is divible by the number of its divisors (144).

It is a Harshad number since it is a multiple of its sum of digits (45).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 33291 + ... + 35829.

Almost surely, 2^87747840 is an apocalyptic number.

87747840 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 87747840, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (155752800).

87747840 is an abundant number, since it is smaller than the sum of its proper divisors (223757760).

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

87747840 is a wasteful number, since it uses less digits than its factorization.

87747840 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2569 (or 2549 counting only the distinct ones).

The product of its (nonzero) digits is 351232, while the sum is 45.

The square root of 87747840 is about 9367.3817046174. The cubic root of 87747840 is about 444.3707640822.

The spelling of 87747840 in words is "eighty-seven million, seven hundred forty-seven thousand, eight hundred forty".