287780 has 12 divisors (see below), whose sum is σ = 604380. Its totient is φ = 115104.

The previous prime is 287747. The next prime is 287783. The reversal of 287780 is 87782.

It is a happy number.

It can be written as a sum of positive squares in 2 ways, for example, as 92416 + 195364 = 304^2 + 442^2 .

It is a hoax number, since the sum of its digits (32) coincides with the sum of the digits of its distinct prime factors.

It is an Ulam number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (287783) by changing a digit.

287780 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 3 ways as a sum of consecutive naturals, for example, 7175 + ... + 7214.

It is an arithmetic number, because the mean of its divisors is an integer number (50365).

2²⁸⁷⁷⁸⁰ is an apocalyptic number.

287780 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

287780 is an abundant number, since it is smaller than the sum of its proper divisors (316600).

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

287780 is a wasteful number, since it uses less digits than its factorization.

287780 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 14398 (or 14396 counting only the distinct ones).

The product of its (nonzero) digits is 6272, while the sum is 32.

The square root of 287780 is about 536.4513025429. The cubic root of 287780 is about 66.0217253241.

The spelling of 287780 in words is "two hundred eighty-seven thousand, seven hundred eighty".