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BaseRepresentation
bin1101111010001
3100202202
41233101
5211441
652545
726522
oct15721
910682
107121
115394
124155
13331a
142849
15219b
hex1bd1

7121 has 2 divisors, whose sum is σ = 7122. Its totient is φ = 7120.

The previous prime is 7109. The next prime is 7127. The reversal of 7121 is 1217.

It is a strong prime.

It can be written as a sum of positive squares in only one way, i.e., 4096 + 3025 = 64^2 + 55^2 .

It is an emirp because it is prime and its reverse (1217) is a distict prime.

It is a cyclic number.

It is not a de Polignac number, because 7121 - 26 = 7057 is a prime.

It is a Sophie Germain prime.

It is a Chen prime.

It is a Curzon number.

It is not a weakly prime, because it can be changed into another prime (7127) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 3560 + 3561.

It is an arithmetic number, because the mean of its divisors is an integer number (3561).

27121 is an apocalyptic number.

It is an amenable number.

7121 is a deficient number, since it is larger than the sum of its proper divisors (1).

7121 is an equidigital number, since it uses as much as digits as its factorization.

7121 is an evil number, because the sum of its binary digits is even.

The product of its digits is 14, while the sum is 11.

The square root of 7121 is about 84.3860177992. The cubic root of 7121 is about 19.2389040456.

Adding to 7121 its reverse (1217), we get a palindrome (8338).

It can be divided in two parts, 7 and 121, that added together give a 7-th power (128 = 27).

The spelling of 7121 in words is "seven thousand, one hundred twenty-one", and thus it is an iban number.