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78289 = 79991
BaseRepresentation
bin10011000111010001
310222101121
4103013101
510001124
61402241
7444151
oct230721
9128347
1078289
1153902
1239381
1329833
1420761
15182e4
hex131d1

78289 has 4 divisors (see below), whose sum is σ = 79360. Its totient is φ = 77220.

The previous prime is 78283. The next prime is 78301. The reversal of 78289 is 98287.

It is a happy number.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4.

It is a cyclic number.

It is a de Polignac number, because none of the positive numbers 2k-78289 is a prime.

It is a super-2 number, since 2×782892 = 12258335042, which contains 22 as substring.

It is an Ulam number.

It is a Duffinian number.

It is not an unprimeable number, because it can be changed into a prime (78283) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 417 + ... + 574.

It is an arithmetic number, because the mean of its divisors is an integer number (19840).

278289 is an apocalyptic number.

78289 is a gapful number since it is divisible by the number (79) formed by its first and last digit.

It is an amenable number.

78289 is a deficient number, since it is larger than the sum of its proper divisors (1071).

78289 is an equidigital number, since it uses as much as digits as its factorization.

78289 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1070.

The product of its digits is 8064, while the sum is 34.

The square root of 78289 is about 279.8017155058. The cubic root of 78289 is about 42.7792909393.

Subtracting from 78289 its product of digits (8064), we obtain a square (70225 = 2652).

The spelling of 78289 in words is "seventy-eight thousand, two hundred eighty-nine".

Divisors: 1 79 991 78289