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7881 = 33771

7881 has 8 divisors (see below), whose sum is σ = 10944. Its totient is φ = 5040.

The previous prime is 7879. The next prime is 7883. The reversal of 7881 is 1887.

7881 is digitally balanced in base 3, because in such base it contains all the possibile digits an equal number of times.

It is an interprime number because it is at equal distance from previous prime (7879) and next prime (7883).

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 7881 - 21 = 7879 is a prime.

It is a super-2 number, since 2×78812 = 124220322, which contains 22 as substring.

It is an Ulam number.

7881 is a lucky number.

It is a plaindrome in base 12.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (7883) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 76 + ... + 146.

It is an arithmetic number, because the mean of its divisors is an integer number (1368).

27881 is an apocalyptic number.

7881 is a gapful number since it is divisible by the number (71) formed by its first and last digit.

It is an amenable number.

7881 is a deficient number, since it is larger than the sum of its proper divisors (3063).

7881 is a wasteful number, since it uses less digits than its factorization.

7881 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 111.

The product of its digits is 448, while the sum is 24.

The square root of 7881 is about 88.7749964799. The cubic root of 7881 is about 19.9003375278.

It can be divided in two parts, 7 and 881, that added together give a palindrome (888).

The spelling of 7881 in words is "seven thousand, eight hundred eighty-one".

Divisors: 1 3 37 71 111 213 2627 7881