247780 has 24 divisors (see below), whose sum is σ = 560952. Its totient is φ = 91392.

The previous prime is 247771. The next prime is 247781. The reversal of 247780 is 87742.

It can be written as a sum of positive squares in 4 ways, for example, as 1764 + 246016 = 42^2 + 496^2 .

It is a super-2 number, since 2×247780² = 122789856800, which contains 22 as substring.

It is a hoax number, since the sum of its digits (28) coincides with the sum of the digits of its distinct prime factors.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (247781) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 217 + ... + 736.

It is an arithmetic number, because the mean of its divisors is an integer number (23373).

2²⁴⁷⁷⁸⁰ is an apocalyptic number.

247780 is a gapful number since it is divisible by the number (20) formed by its first and last digit.

It is an amenable number.

247780 is an abundant number, since it is smaller than the sum of its proper divisors (313172).

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

247780 is a wasteful number, since it uses less digits than its factorization.

247780 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 975 (or 973 counting only the distinct ones).

The product of its (nonzero) digits is 3136, while the sum is 28.

The square root of 247780 is about 497.7750495957. The cubic root of 247780 is about 62.8090294940.

The spelling of 247780 in words is "two hundred forty-seven thousand, seven hundred eighty".