47781 has 6 divisors (see below), whose sum is σ = 69030. Its totient is φ = 31848.

The previous prime is 47779. The next prime is 47791. The reversal of 47781 is 18774.

It can be written as a sum of positive squares in only one way, i.e., 25281 + 22500 = 159^2 + 150^2 .

It is not a de Polignac number, because 47781 - 2¹ = 47779 is a prime.

It is a super-2 number, since 2×47781² = 4566047922, which contains 22 as substring.

It is a plaindrome in base 12 and base 14.

It is a nialpdrome in base 16.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (47701) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 2646 + ... + 2663.

It is an arithmetic number, because the mean of its divisors is an integer number (11505).

2⁴⁷⁷⁸¹ is an apocalyptic number.

It is an amenable number.

47781 is a deficient number, since it is larger than the sum of its proper divisors (21249).

47781 is a wasteful number, since it uses less digits than its factorization.

47781 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 5315 (or 5312 counting only the distinct ones).

The product of its digits is 1568, while the sum is 27.

The square root of 47781 is about 218.5886547834. The cubic root of 47781 is about 36.2870568340.

It can be divided in two parts, 47 and 781, that added together give a palindrome (828).

The spelling of 47781 in words is "forty-seven thousand, seven hundred eighty-one".